12 / PART ONE: THE BASICS Identifying non-finite verbs The infinitive The non-finite verbs are the infinitive , the present participle and the past participle . The infinitive is the form of the verb that has ‘to’ before it: To run, to dance, to write, to publish, to dine. If an infinitive is used in a sentence, there must be a finite verb as well. The infinitive cannot stand alone. Look at the following: To run in the London Marathon. This is not a sentence because it contains only the infinitive. There is no finite verb. Here is the corrected version. He decided to run in the London Marathon. This is a sentence because it contains ‘decided’, a finite verb. This has a ‘person’ connected to it and is in the past tense. Many people consider it incorrect to ‘split’ an infinitive. This is when a word is placed between the ‘to’ and the verb: It is difficult to accurately assess the data. The following example is better. The infinitive has not been ‘split’ by the word ‘accurately’: It is difficult to assess the data accurately.