A non-finite verb (sometimes called a verbal) is any of several verb forms that are not finite verbs; that is, they cannot serve as the root of an independent clause. The non-finite verb forms found in English are infinitives, participles and gerunds; additional such forms found in some other languages include gerundives and supines. Non-finite verbs are typically not inflected for tense, and compared with finite verbs usually display less inflection for other grammatical categories as well.[1] They also typically lack a subject dependent. A typical finite clause is based on a single finite verb, but it may in addition contain one or more non-finite verbs, building a verb catena with the finite verb. Since English lacks inflectional morphology to a large extent, the finite and non-finite forms of a given verb are often identical. In such cases, one has to examine the environment in which the verb appears to know whether it is finite or non-finite. The following sentences each contain one finite verb (underlined) and multiple non-finite verbs (bolded): The proposal has been intensively examined today. What did they want to have done about that? Someone tried to refuse to accept the offer. Coming downstairs, she saw the man running away. In the above sentences, been, examined and done are past participles, want, have, refuse and accept are infinitives, and coming and running are present participles (for alternative terminology, see the sections below). In languages like English that have little inflectional morphology, certain finite and non-finite forms of a given verb are often identical, e.g. a. They laugh a lot. - Finite verb (present tense) in bold b. They will laugh a lot. - Non-finite infinitive in bold a. Tom tried to help. - Finite verb (past tense) in bold b. Tom has tried to help. - Non-finite participle in bold Despite the fact that the verbs in bold have the same outward appearance, the first in each pair is finite and the second is non-finite. To distinguish the finite and non-finite uses, one has to consider the environments in which they appear. Finite verbs in English usually appear as the leftmost verb in a verb catena.[2] For details of verb inflection in English, see English verbs. [edit]Types of non-finite verbs English has three kinds of non-finite verbs: infinitives, participles, and gerunds Each of these non-finite forms appears in a variety of environments. The infinitive of a verb is considered the "base" form; it is the form that is listed in dictionaries. Infinitives in English appear in verb catenae where they are introduced by an auxiliary verb or by a certain limited class of main verbs. They are also often frequently introduced by a main verb followed by the particle to (as illustrated in the trees above). Further, infinitives introduced by to can function as noun phrases, or even as modifiers of nouns. The following table illustrates these environments
