English In English, a nonfinite verb form may constitute: • an infinitive verb, including the
auxiliary verb have :# within a
verb phrase that is predicated by a
modal verb (e.g., "I could
have cried"). :# within a to-infinitive phrase (e.g., "They seem to
have moved"). • a
participle. • a
gerund. Each of the nonfinite forms appears in a variety of environments.
Infinitive The infinitive form of a verb is considered the
canonical form listed in dictionaries. English infinitives appear in verb catenae if they are introduced by an auxiliary verb or by a certain limited class of main verbs. They are also often introduced by a main verb followed by the particle
to (as illustrated in the examples below). Further, infinitives introduced by
to can function as noun phrases or even as modifiers of nouns. The following table illustrates such environments: :::
Participle English participles can be divided along two lines: according to aspect (progressive vs. perfect/perfective) and voice (active vs. passive). The following table illustrates the distinctions: ::: Participles appear in a variety of environments. They can appear in
periphrastic verb catenae, when they help form the main predicate of a clause, as is illustrated with the trees below. Also, they can appear essentially as an adjective modifying a noun. The form of a given perfect or passive participle is strongly influenced by the status of the verb at hand. The perfect and the passive participles of
strong verbs in
Germanic languages are irregular (e.g.,
driven) and must be learned for each verb. The perfect and passive participles of
weak verbs, in contrast, are regular and are formed with the suffix
-ed (e.g.,
fixed,
supported,
opened).
Gerund A gerund is a verb form that appears in positions that are usually reserved for nouns. In English, a gerund has the same form as a progressive active participle and so ends in
-ing. Gerunds typically appear as subject or object noun phrases or even as the object of a preposition: ::: Often, distinguishing between a gerund and a progressive active participle is not easy in English, and there is no clear boundary between the two nonfinite verb forms.
Auxiliary verb Auxiliary verbs typically occur as
finite verbs, but they also can occur as a participle (e.g.
been,
being,
got,
gotten, or
getting) or, in the case of
have, in a nonfinite context as the complement to a modal verb relating to a
perfect tense, e.g.: :::
Native American languages Some languages, including many
Native American languages, form nonfinite constructions by using
nominalized verbs. Others do not have any nonfinite verbs. Where most European and Asian languages use nonfinite verbs, Native American languages tend to use
ordinary verb forms.
Modern Greek The nonfinite verb forms in
Modern Greek are identical to the third person of the
dependent (or aorist subjunctive) and it is also called the
aorist infinitive. It is used with the auxiliary verb ("to have") to form the perfect, pluperfect and future perfect tenses. ==Theories of syntax==