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Too Good to Be True: A Case Study of “Zui Hao Shi”

This paper aims to investigate the polysemy and multifunctionality of the expression “最好是”. It has been observed in recent years that “最好是” has two different meanings and semantic-pragmatic functions. The first function is to express speaker’s suggestion or expectation to the hearers to reach the optimal outcome. It is noted as the deontic optative meaning by Bybee (Bybee et al. 1994). As this meaning expresses expectation to the events in a hypothetical world, the deontic “最好是” also functions as a conditional marker (Traugott 1983). The other meaning of "最好是" is the epistemic meaning. The epistemic meaning of "最好是" performs the indirect speech act to show the speakers' denial or disbelief brought forth by the interlocutor. The paper is to argue that the epistemic meaning of “最好是” derives from the deontic meaning. This semantic change is motivated by subjectification of the semantic implication of deontic meaning, which consists of implicature of “not yet done” and “too good to be true”. The data for this paper consists of three main sources: on-line corpus (Academia Sinica Balanced Corpus), Internet (google and yahoo), and conversation data. The three databases consists of different types of discourse (written and spoken) and different levels of formality. The observation from the data shows that the process of semantic change of "最好是" follows the path of semantic change proposed by Traugott and Dasher (2002). The epistemic meaning of " 最好是" derives from the deontic meaning as the result of subjectification of the semantic implications (Traugott 1999). The distribution of data also points out that the epistemic “最好 是" is informal and requires an interactional context while the deontic “最好是" appear much more frequently in formal context and written discourse. At last, according to the data, it is proposed that the epistemic “最好是" should be established as an epistemic formula. This formulaic form of “最好是” functions as verbal irony. It serves as an option for politeness strategy (Brown and Levinson 1987) to soften and counter direct criticism, complaints, and disbelief.


Introduction
It has been observed that the expression " " has two different meanings and semantic-pragmatic functions. One function is to show speaker's expectation or suggestion toward an event or an action. This function has the deontic meaning of expressing wish and desire. By using this function speakers show their intended hearers what is necessary to be done or to be possessed to achieve the optimal outcome. This function is illustrated below: (1) a. 便 療 (Academia Sinica Balanced Corpus) b.
旅行 兩 行 (Academia Sinica Balanced Corpus) It is observed that both examples in (1) are suggestions or expectations for the hearers. In (1a) it is suggested or expected that for the best outcome of medical treatment it is best to diagnose the problem early. In (1b) it is suggested that to backpack one better have two or more companions to go with so they can look after one another during the trip. From the two examples it is readily shown that what is suggested or expected can be either an action or a property.
The second function of " " is as an epistemic formula. It functions to sarcastically deny or reject a proposition brought up by the interlocutors (2a) or existent in the situational context (2b). The use of this function is frequently observed among the young population (college students and high school students).
(2) a. A: 參 B: b. (on seeing a dog sleeping with it belly up) This paper is to argue that the epistemic formula " " derives from its deontic meaning of suggestion and expectation toward hearer's obligation. The epistemic meaning emerges from on-line communication not only due to the rise of subjectivity (Traugott 1999) but also due to the integration of the well-entrenched concept of "too good to be true". Moreover, from a pragmatic-cognitive perspective this paper will attempt to examine that the multifunctionality of the expression " " is based on mechanisms such as conditionality and politeness principle.
The data for this study consist of three different sources. The first source is the data collected from Academia Sinica Balanced Corpus. As the concordance is unable to recognize " ", the search is done by keying in " ". Of all the 498 tokens 64 of them are " ". The second source is the web search in google.com. The web search generated more than 6 million results. The first one hundred results are taken for this study. The third source is the personal notes of daily conversation. The notes contain 42 instances of " ". The conversation data consists of mainly conversations between university students. The data collection and classification is done with the help of two other students in National Taiwan Normal University. In the later discussion, the data from different sources will be noted. This notation of data is first to recognize the source of data. Also the recognition of the source would also be able to indicate the interactional nature of the expression " ". The paper is organized as follows. Section 2 reviews the approaches and mechanisms which are crucial to the study of semantic change. Section 3 categorizes the expression " " into two types: deontic " " and epistemic " ". Section 4 proposes that the semantic change of " " involves not only subjectification but also semantic implication. Section 5 is the analysis of the distribution of two types of " ". Section 6 draws a conclusion to the paper.

Overview of Semantic Change
In this section two topics will be covered. First is the unidirectionality of the semantic change of modality and subjectivity. The second is Hopper's (1991) approach to semantic change.

2-1 The Unidirectionality of Semantic Change
Traugott and Dasher (2002) stated that semantic change has a lot to do with two aspects of language. The first is modality, the second is subjectivity.
Modality, according to Kiefer (1994) "consists in the relativization of the validity of sentence meanings of a possible world." (p.2515) Modality can generally be separated into two categories: deontic modality and epistemic modality. Deontic modality concerns mainly about obligation or compulsion. Lyons (1977) identified the characteristics of deontic modality as concerned with the possibility and necessity of the actions performed by a morally responsible agent. It describes the state-of-affair that will obtain when the action in question is performed and it typically proceeds or derives from either outer or inner compulsions.
Another kind of modality presented in Traugott and Dasher (2002) is the advisability. Advisability is the sense that the action to be performed by the agent is not only normatively wished but also be profitable to the agent. They discovered that the advisability modality plays an important role in the development of modals in English and Japanese. Bybee and her colleagues (1994) examined deontic modality in a more detailed fashion. They divided deontic modality into two parts: agent-oriented modality and speaker-oriented modality. Agent modality includes a. Oligation, b. Necessity, c. Ability, d. Desire. The speaker-oriented modality includes a. imperative b. prohibitive, c. optative, d. hortative, e. admonitive, and f. permissive modality. What should be noted is the optative modality. Optative modality expresses speaker's wish and hope toward a hypothetical world. As will be seen in the later discussion it will be shown that the deontic meaning of " " is mainly optative modality.
Epistemic modality, on the other hand, is largely concerned with speaker's knowledge and belief. According to Traugott and Dasher (2002), epistemic expressions are used to express speaker's commitment to the truth of the proposition. For example, the sentence "John must be tired." is a strong epistemic expression for it reflects the speaker's belief of John being tire is firm. A weak epistemic reading can be exemplified by the sentence "John may be tired." In this sentence the state of belief of John being tired is not so high in degree. Traugott (1989), examined the process of semantic change of English words allow and evidently. She concluded with the general process of semantic change. It is shown in (i) (i) main verb > premodal > deontic > weak epistemic > strong epistemic This general process of semantic change is later confirmed in Traugott and Dasher (2002). The semantic change of modals must and ought to are examined. They concluded that the process of semantic change is that epistemic meaning derives from deontic meaning. The process is unidirectional. In other words, the process can not be reversed.
Another key issue in semantic change is subjectification. According to Lyons (1982), subjectivity refers to the way in which languages provide expressions of the attitudes and beliefs of a locutionary agent. Traugott (1989) identifies three tendencies of grammaticalization, in which meanings may change from propositional to textual or to expressive meanings. The third tendency she identifies is cited below: Tendency : "Meanings tend to become increasingly based in the speakers subjective belief state/attitude toward the proposition. " (1989:p.35) In Traugott (1999), she defines the process of subjectification as how meaning is increasingly based on the subjective belief and attitude toward what is being said and what is being said. In other words, subjectivication is the process in which meanings tend to encode or externalize the speaker's perspectives and attitudes within the hypothesized world rather than the real world.
In Traugott and Dasher (2002), it is concluded that as the deontic meaning changes to epistemic meaning, the subjectivity will rise at the same time. In this way, the process of semantic change can be summarized as in (ii): (ii) epistemic meanings derive from deontic meanings, meanwhile the subjectivity becomes higher It should also be noted that unidirectionality is also true with subjectivity. So in the process subjectivity only gets higher, not vice versa.

2-2 Hopper's Approach to Semantic Change
The path of semantic change identified by Traugott and Dasher (2002) is well supported by diachronic data. What about semantic changes in languages or meanings that are present but not available in written documents? There are many languages do not have a written forms or documents of their languages. Also even for languages that have written forms the new meaning may only exist in spoken data. According to Hopper (1991), synchronic approach to semantic change or grammaticalization is possible based on the tendency from cross-linguistic observation.
He also proposes several principles to deal with grammaticalzation. One of the principles is the "layering" principle, which states that the new meanings and the old meanings in the process of semantic change can co-exist. New meanings do not immediately replace old ones. In this way the cognitive-pragmatic reconstruction of synchronic spoken data is likely to draw some clues.

The Taxonomy of " "
From the collected data, two main meanings of " " are observed. The two meanings will be presented and discussed respectively in section 3-1 and 3-2.

3-1 Deontic Meaning:
The first meaning of " " observed in the data is the deontic meaning. The deontic meaning is used to express one's will. The function of this meaning is for one to express one's wish, desire, and suggestion to a certain issue or proposition. Here the issues or propositions are the desired situations or conditions that the speakers seek for the profit of theirs or the addressees. The following are some examples: ( 便 (Academia Sinica Balanced Corpus) In example (3a), the speaker is looking for a teammate to play tennis. Also he expects the teammate to be of the opposite sex. This wish is revealed by the linguistic coding of using " " before the desired condition. In (3b) the speaker is looking for stories about the Trojan War. Here he is not only asking for a story but also expecting the story to be one based on real history. Again his wish is specified by the use of " ". In these two examples, instead of integrating the desired condition into the main clause, the speakers choose to separate the desired condition from the main clause and add the expression " ". In this way the desired condition is highlighted. In (3c) and (3d), both speakers expect a desired optimal condition (a clear day, a wealthy husband) for their wish to come true. The use in (3c) and (3d) differ from (3a) and (3b). What is different is that in (3a) and (3b) " " is used to directly code the desired entity or condition. However, in (3c) and (3d), " " is used to code the premises for the desired condition to come true. The use of " " in (3c) and (3d) are more like conditional markers. This function of conditional marker will be discussed latter in 3-1.1.
In examples (3e), (3f), and (3g) the expression " " performs to give suggestion. One of the deontic meanings listed in Traugott and Dasher (2000) is advisability. Advisability includes the sense that the action sought of is not only normatively wished but also beneficial to the one to carry it out. Take (3f) for example. It tells the addressee it is not only necessary to wear conservative clothing when visiting a mosque, but it would be best or beneficial for visitors to wear long sleeves and long skirts to avoid troubles.
The difference between the function of expressing wish/desire and the function of giving suggestion is the difference of degree. The expression of wish and desire, according to Bybee et al (1994) is a subcategory of speaker-oriented deontic modality named optative modality. On the other hand, the function of giving suggestion is of the agent-oriented modality of obligation and necessaity, in which social or physical need would compel the agent (in the case the addressee) to perform the predicate actions. When expressing wish and desire, the hope (subjectivity) that the desired condition to true is usually very strong. This is because the desired condition is often beneficial to the speaker himself. On the other hand, when giving a suggestion the hope for the desired condition is not so strong in comparison to wishing. The difference in degree here is due to the fact that when giving suggestions the desired condition may not be directly profitable to the speakers themselves but to the addressees. As the speakers are not the ones benefited from the accomplishment of the desired situation, the motivation and the hope for it to be true will not be high.
There are also instances of deontic " " is used for the function of threatening. As the following example: (4) 說 不 了 (personal notes) This threatening function can be viewed as a peripheral type of advise/suggestion. It can be interpreted as that the speaker suggests the addressee to fulfill the premises (in the case, the talking) or something very bad will happen to him. The same as the instances of suggestion, the cases of threaten function to give advice for the benefit of the addressee.

3-1.1 Conditionality and Desirability of " "
It has been mentioned in that the deontic meaning of " ", expressing wish and desire, behaves like a conditional marker. Here are some more examples: (google.com) Traugott (1983) stated that many lexical sources can become conditional markers. One of the sources is modality, especially optative modality that expresses wish and desire. Conditionals are about the hypothetical worlds. It is true that imagined hypothetical worlds are often ones that are wished for by the speakers. This is why optative modality can be motivated to be a conditional marker. As we see in example (5a) and (5b), both of the two instances put forward a desired condition (students being able to vote for university principal, keeping slim). These conditions are the imagined or hypothesized world wished for by the speakers. For the imagined or hypothesized world to come true some premises have to be done in the first place. The clauses with " " provide the premises for the desired condition to be fulfilled. The conditional marker function of deontic " " arises as it is to provide the premises for the hypothesized scenarios wished for. Furthermore, it is noteworthy that when the deontic meaning of " " is used, the expected/suggested premises is not yet fulfilled. The desired outcome is, therefore, far from being accomplished. It can be viewed as a kind of the "predictive" conditionals, which predicts that if a desired/undesired action is carried out or a desired/undesired condition is fulfilled, the desired/undesired consequence will take place. Clancy et al (1997) observes that in American English, Japanese, and Korean, children less than three years old are given warnings or advices in the reasoning process cited below: (iii) It is desirable that p will happen. If "not p" happens, it will lead to undesirable consequences. Akatsuka and Strauss (2000) also states that speaker's stance of desirability is how people understands the various usages of conditional utterances in daily lives. It is through the reasoning process of described in (iii) that people understand the conditionality in utterances.
In this case of deontic modality of " " desirability is crucial to the functions the expression performs. Take (5b) for example, the line of reasoning can be recorded in the format similar to (iii) and it will look like the one in (6) (6) It is desirable that p (one being relaxed) will happen. If p happens, it will lead to the desirable consequence (keeping slim). Example (4) can also be put in the same line of reasoning as (iii). The outcome is as (7): (7) It is desirable that p (speaking quickly) will happen. If "not p" happens, it will lead to the undesirable consequence (being done for). In this way the inclusion of undesirability is the difference between the pragmatic functions of advising and threatening. We can see that the use of " " as a conditional marker often involves premises and outcomes. For example, in (5b) the premise is "to relax" and the outcome is "keeping slim". The premises are always what are required for the desirable outcome. If the outcome is the desirable one, then " " functions to give advise and suggestion. If the outcome is the undesired one, " " would function to be a threat.

3-2 Epistemic Meaning:
As have mentioned, epistemic meaning is largely concerned with the knowledge state or subjective belief. It is mainly about the speaker s evaluation or judgments on the truth of the proposition. The epistemic meaning of the expression " performs the indirect speech act of rejection or denial to the proposed proposition. It shows that speakers are not holding the evaluated propositions to be desired, rightful, or true.
The following are some examples: (personal notes) Example (8a) shows that B does not take A's proposition of her being a person with mixed ethnicity to be true. At least she does not think that her curly hair is symbolic of a typical hybrid (European-Asian, for example). That is why after she sounded the denial with " " she added another comment. That comment shows that she opposes the proposition brought up by A. Example (8b) and (8c) are similar ones.
In both examples the denied proposition are repeated after the expression " ". It shows that in this kind of context it is the proposition brought about by the interlocutors (secret dating; survive the course without previewing the material) that are denied, not other elements of the previous statement. It is through this kind of instantiation that the negative reading of " " can be inferred. (8d) shows that the proposition denied can be not only a single proposition but also a whole article. (8e) is another convincing instance that " " is used to deny the truth or validity of a previously proposed idea. Most of the instances of epistemic " " take the formulaic-like form in the observed daily conversations.

The Process of Semantic Change of " "
In Traugott (1989Traugott ( , 1990 and Traugott & Dasher (2002) the unidirectionality of semantic change is proposed. Using examples like allow and evidently, Traugott (1989) discovered the direction of change of these words. Both these words go through the stages as illustrated in (iiii).
(iiii) deonitc meaning > object epistemic > strong epistemic Note that not all the stages have to take place for the process to be complete. The general pattern of the change, as noted by Traugott and Dasher (2002), is that epistemic meaning derives from deontic meaning, not vice versa. Meanwhile subjectivity increase as the epistemic meaning derives from the deontic meaning.
In the case of " ". It starts out to have a deontic meaning. The deontic " " functions as a conditional marker to give advises or suggestions. These suggestions and advises aim to guide the hearers to achieve the desired optimum. Also as conditionals the suggestions are given in the hope that the optimum would come true in the hypothetical world. It is clear then at the time a speaker uses " " the required premises (actions, properties) is not yet available and the desired outcome not yet accomplished. In other words, there is this implicature that the situation is irrealis. Akatsuka (1985), in the discussion of conditional and counterfactual reasoning, states that the conceptual domains of realis and irrealis have to do with one's epistemic evaluation. These two domains affect speaker's evaluation of the realizability of an event. In this way, subjectively one is capable of using this implicature to show that he knows that the event is not true. Hopper and Traugott (2000) point out that in early stages of grammaticalization the implicatures often become part of the semantic meaning of a form. In this case " " the implicature of "not yet ture" or "not done" is clearly the sources of the epistemic use of " " as a means to show disbelief. Meanwhile in the process as subjectivity of the speaker becomes higher the meaning will move toward the speaker's strong belief or disbelief of the event. In this case the semantic implicature is strengthen by the sujectification of meaning in the change from deontic " " to epistemic " ". The other source of semantic implication is the well-entrenched concept of "too good to be ture". In Traugott (1989), she suggested that the shift from deonitc meaning to epistemic meaning is done through the conventionalization of the conversational implicature. She stated that this conversational implicature is used in speaker's attempt to regulate communication with others. Levinson (2000) provided a more comprehensible definition of conversational implicature. For Levinson, the conversational implicature is a default inference "…that captures our intuitions about a preferred or normal interpretation." (p. 11). Then, what is the implicature that leads the epistemic meaning to a negative one? It is the cognitive factor that leads to the negative reading. As Langacker (1987) and Johnson (1987) pointed out, cognitive machenisms are often involved in the process of semantic change. They both proposed that the integration of familiar information to make sense of the new experience is a very basic process. Here the integrated concept is a well-entrenched one "too good to be true". The expression " " often denotes an optimal condition which is desired by the speaker. However, everyone knows that the optimum is often hard to reach. For example, it is impossible to form an optimal rule without exception. Also it would be impossible for everything to go smoothly the way one expects. If anything can go wrong, it will. This implicature is best illustrated by (9): (9) 樂樂 不 (Academia Sinica Balanced Corpus) Therefore the optimum would often be related to those tasks that are impossible. It becomes predictable then, that when one proposes something that looks perfect, it is usually impossible. As the implicature becomes more deeply rooted in one's subjective belief, the conceptual connection between optimum and impossible is thus linked and integrated. In this way, when one proposes something that is optimal one is actually proposing something impossible. When the concept of "too good to be true" in integrated into the interlocutors, they would automatically connect the optimal meaning with disbelief, especially when the optimal proposition sounds untrue, undesired, or invalid to the interlocutor (which is the case with the epistemic " "). Take (10) for example: (10). A: 不 ? B: (personal notes) In (10), the proposition brought up by A, to work on research papers all day long, would sound to B (and most others) to be very good, but impossible (or even exaggerating). Therefore B would see the optimal proposition of working on research papers all day long as untrue. With the concept "too good to be true" integrated to his mind, B would automatically treat the incoming material as not true and assign the negative meaning of disbelief/denial to the proposition to the expression of " ". Overall, we can see that the motivation of " " is mainly semantic implicature. It is implied that when one uses " " the suggested qualification is not fulfilled and the desired outcome therefore not reached. The other semantic implication is that the outcome brought up by " " is often too hard to reach in real life. When these two implicatures are "semanticized" to add new meaning of " ", the new meaning of disbelief or denial emerges in order to express speaker's subjective evaluation.

" " as an Epistemic Formula
This part of the paper discusses the property of " " as an epistemic formula. It will also be discussed why among so other possible collocations with " " it is in " " that epistemic emerges. The third part of the analysis will draw reference to the politeness theory (Brown and Levinson 1987)

5-1. The Epistemic Formula " "
The end point of semantic change or grammaticalization is often that a lexical item becomes grammaticalized and becomes a discourse marker. Discourse markers, according to Schffrin (1986), are "sequentially dependent elements which brackets units of talk" (p.31). They have lost their lexical meaning during the process of grammaticalization. Their functions are primarily discourse-oriented, such as turn-taking, topic-management, or discourse organizing.
This, however, is not the case with the epistemic " ". It is obvious that thought the meaning is altered the lexical meaning of epistemic " " still exists. It is more appropriate to call it an epistemic formula. Both Bolinger (1976) and Fillmore (1967) noted that a large portion of language is memorized, automatic and rehearsed rather than created, generated, or freely put together. Coulmas (1979) termed these automatically produced parts of language as "routine formula". They are lexically and syntactically unchangeable groups of words. They are situationally-bound utterances to perform pragmatic functions such as greeting (e.g. good morning) or politeness (e.g. thank you).
Judging from these criteria, the epistemic " " looks fit as an epistemic formula. First, the lexical meaning of denial or disbelief is fixed. Second it always occupies the clause-initial position. The situations in which they are used is when an optimal proposition is brought forth by the interlocutor that is untrue, invalid or undesired for the evaluation of the speaker.
Of all the 46 tokens of epistemic " ", 31 of them are used alone without the repetition of the denied proposition. Two theories provide convincing explanation for the formation of the formula. First, Givon (2001) states that reduced expressions are favored when the speaker is biased. The more the speaker is biased the more reduced the form will be. Here " " serves as a good example. As the speakers are biased not to believe the possibility and probability of the proposition they would choose the minimal form. Second, Traugott (1995) and Traugott and Dasher (2002) proposes that In on-line communication (in which the instances of epistemic " " are observed) the speakers invite their interlocutors to make inferences (invited inference) on their subjective evaluation of the current speech situation. Meanwhile hearers make the most effort to infer what is meant by the speakers. As long as the invited inference is semanticized it is predictable, the new meaning can be used for most informativeness with minimal linguistic coding. In the case of " ", once the negative reading is established from the interaction, the denied or rejected propositions no longer have to be repeated.

5-2 Why " "?
From the previous analyses it is clear that the semantic change of " " is the result of the semantic implication of " " and subjectification. However, there are many other possible collocations with " ". The following are examples of the most frequent collocations with " " from the Academic Sinica Balanced Corpus: " the tokens are the times of their appearances immediately following " " ( , , 不 etc.). The ones that do not follow immediately " " are excluded for the purpose to see why only " " undergoes semantic change. It is very likely that the reason lies in the different kinds of components following those words. From the data collected from the Academia Sinica Balanced Corpus, it is possible to look into the types of components these words introduce. First look at the three words " ", "不 ", and " ".
立 (Academia Sinica Balanced Corpus) The verb " " is a copula verb denoting ability. From the data it is observed that all the instances of " " are accompanies with a verb. The meaning of " " is then the expectation that some action is to be taken for the desired optimum. The meaning of the verb " " then restricts the kind of proposition that follow it to only those related to actions i.e. verb phrases. " 不 " shows a similar patter with " ". 46 of the 47 instances takes the construction of " 不 +VP". For instance: (12) a.
There is also an instance of " 不 " in the clause-final position: (13) 不 (Academia Sinica Balanced Corpus) When placed in the clause-final position like the one in (13), the VP that is omitted following " 不 " can be found in the preceding clause. The components that follow " 不 " are always VPs in the Academia Sinica Balanced Corpus. Now look at the third collocation " ". All the instances in the corpus of " " are followed by noun phrases (NPs). As shown in (14): (Academia Sinica Balanced Corpus) c. 例 (Academia Sinica Balanced Corpus) It appears that the three collocations " ", " 不 ", " " are biased in the components that they introduces. " " and " 不 " always introduce VPs. " " introduces NPs. On the other hand, " " can introduce a wider variety of components. For instance, it can introduce a full clause like (15) cited below: (15) 什 什 (Academia Sinica Balanced Corpus) It is also able to introduce VPs like (16a)  ", among other frequent collocations, can introduce more variety of components. It is in this sense semantically and syntactically more general than other collocations. As speakers use " " it includes the functions of other collocations. It is why among the many collocations " " it chosen to undergo semantic change.

5-3 " " as Verbal Irony.
It has been discussed in 3-2 that the epistemic " " functions to perform the indirect speech act. The form " " would look like the speaker see the proposition brought up by the interlocutor or in the situational context to be desirable. The actual meaning is that the proposition is to the speakers as untrue or undesirable. This function can be viewed as an ironical function. According to Sperper and Wilson (1995), verbal irony is "invariably the rejecting and the disapproving kind (p.237)". The speakers of uses verbal irony to disassociate themselves from the proposition echoed and indicate that they do nit hold the proposition to be true. Sperper and Wilson put forth that there are three requirements in understanding verbal irony. First is to recognize the speech as echoeic. Second is to identify the source of echoed opinion. Third is to recognize the speaker attitude as rejection and disapproving. We can use these three criteria to examine " " as verbal irony. Let's look at examples (8b) and (8c): 8b. A: B: (personal notes) 8c. A: 不 survive B: 不 行 (personal notes) In both examples the rejected proposition is echoed. In (8b) the assumption of the secret dating that is echoed. In (8c) it is the opinion of being able to survive the course without previewing the material that is echoed. The propositions in both examples are from the other interlocutors. The propositions from the other interlocutors in both are rejected by the sentence containing " ". Besides verbal irony, the epistemic meaning of " " has another pragmatic function. It is recognized by Brown and Levinson (1987) that indirect speech and verbal irony are both strategies of politeness. Politeness is way to soften or to counter the effect face-threatening acts (FTAs). Indirectness can save face by allowing speakers to avoid responsibility for the potentially face-damaging interpretation of the utterance. By using indirect speech the speech act is not directed to the the hearer as the speaker do not really commit to the utterances. Also by using irony to express criticism, disapproval, and complaint can be thought of as a softening a threat to the positive face of the hearer. It is also noted that the use of indirectness and irony is often among intimates or close friends. " " in this sense, is also able to soften negative feelings. It is not a direct criticism or rejection such as "不 ", "不 ", or "不行". It is also observed that of the tokens which " " is used as verbal irony 38 of them are used between classmates and friends and the other one is used between mother and child. These observations shows that " " as verbal irony to perform indirect speech act of denial, rejection or disbelief is a politeness strategy used among close friends or intimate individuals.

The Distribution of " "
The distribution of the deontic and epistemic " " in different data collections is shown in Table 2. ) Of all the data, the data from Academia Sinica Balanced Corpus consists of mainly written discourse, which is the most formal set of data. The data from google.com contains a variety of sources and is regarded as with mixed formality. The personal notes are all face-to-face interaction data among peers (only one of the token is between mother and son). It is deemed the least formal set of data. From the distribution data it can be concluded that the epistemic " " takes place mainly in interaction situations. On the other hand, the deontic meaning of " " enjoys wider distribution in all three sets of data. The distribution is in itself capable of showing the nature of the different situations. In daily, face-to-face discourse, the exchange of ideas is often very rapid. As there are exchanges of ideas there would inevitably be confrontations. This rapid pace of discourse and potential of ideational confrontation would promote the use of the short epistemic formula " ". On the other hand, as there is often not need of seeable change of ideas in written course (ideas often go unidirectionally from the writer to the reader), no confrontation would take place and therefore not necessay to use the epistemic formula " ". As to the deontic " ", the function of expressing wish, desire or suggestions are universal no matter what discourse type it would be. Therefore the deontic " " enjoys a wider distribution.

Summary and Conclusion
The process of semantic change of the expression " " confirms the process proposed by Traugott and Dasher (2002). From the data collected from spoken discourse and written corpus, it is observed that different layerings of meaning co-exist in contemporary Mandarin Chinese. The epistemic meaning of " ", the one expressing speaker's denial and disbelief toward a proposition, derives from it's deontic meaning, which is mainly the optative modality of expressing wish and desire. This process is motivated by the semantic implication of "not yet ture" and "too good to be true". The process is completed by subjectification that makes the usage move toward the speaker's subjective evaluation of the proposition. It is through these two processes that the negative meaning (denial and disbelief) rather than the positive (strong belief) of the epistemic " " would come about. The distributional data show that the epistemic " " is strongly interaction-oriented. It mainly takes place in conversations when exchange of propositions and confrontations are available. As " " is to denote a desired condition in the hypothesized world, it can be used as a conditional marker in its deontic sense. This deontic meaning and conditionality brings the assumption of a hypothetical world. It is this conditionality that allows speakers to grasp the implicatures that would motivate the semantic change.
The epistemic " " can be used as an epistemic formula. It can be used under the situation in which a proposition, which is viewed by the speaker as not true or invalid, is proposed to deny and show speaker's disbelief. The usage of " " in isolation as an epistemic formula is the invited inference. It is through the invited inference that hearers can understand speaker's intention of expressing subjective evaluation. As long as the inference is semanticized and predictable, the meaning of epistemic " " as denial or rejection is then stable and isolated use is understood by other hearers. As a formula it also is a politeness strategy owing to its nature of indirect speech act and verbal irony. As an indirect speech act it allows the speaker to not directly commit to the utterances that aim to criticize or to reject. As verbal irony it softens the strong negative feeling of direct rejection, criticism, and disbelief.
To sum up, the epistemic meaning of " " emerges from the deontic use. The conditionality expressed in the deontic function contains implicature that the desired outcome is not yet achieved and is too good to be true. As subjectivity rises the epistemic function of expressing speaker's denial and disbelief takes place. The use of " " to express subjective evaluation is then stabilized through invited inference. The epistemic meaning is also used as a formula in situations which requires the expression of disbelief and denial. The present study confirms the unidirectionality of semantic change and investigates the semantic-pragmatic properties of such shift in meaning.