Auxiliary verbs usually accompany a main verb. A particularly hard verb tense to remember is command verbs. It is a noun coming from a reflexive verb. Affixes are categorised into noun, verb, and adjective affixes. The term can be used as a verb or noun for the operation. The name comes from the Japanese verb and noun . Subject nouns generally come before the verb. A verb itself indicates no grammatical tense. This mnemonic helps students attempting to memorize different verb tenses. Most languages have a number of verbal nouns that describe the action of the verb. Some languages have distinct irrealis grammatical verb forms. For constructions with consecutive verb phrases containing the same verb, see under Adverbs. This is a list of Japanese verb conjugations. It had analytic features like definite and indefinite articles and periphrastic verb conjugation. The potential "-ru" ending conjugates as a vowel stem verb.