Every grammatically correct sentence or clause must contain a finite verb; sentence fragments not containing finite verbs are described as phrases.

Some interjections can play the same role. Even in English, a sentence like Thanks for your help! has an interjection where it could have a subject and a finite verb form (compare I appreciate your help!).

In English, as in most related languages, only verbs in certain moods are finite. These include:

* the indicative mood (expressing a state of affairs); e.g., "The bulldozer demolished the restaurant," "The leaves were yellow and stiff."

* the imperative mood (giving a command).

* the subjunctive mood (expressing something that might or might not be the state of affairs, depending on some other part of the sentence); nearly extinct in English.

A verb is a word that expresses an occurrence, act, or mode of being. Finite verbs, sometimes called main verbs, are limited by time (see tense), person, and number.

The finite verbs are highlighted in the following sentences:

The bear caught a salmon in the stream.

Who ate the pie?

Stop!

A nonfinite verb form - such as a participle, infinitive, or gerund - is not limited by by time (see tense), person, and number.

Verb forms that are not finite include:

* the infinitive

* participles (e.g., "The broken window...", "The wheezing gentleman...")

* gerunds and gerundives

In linguistics, a non-finite verb (or a verbal) is a verb form that is not limited by a subject; and more generally, it is not fully inflected by categories that are marked inflectionally in language, such as tense, aspect, mood, number, gender, and person. As a result, a non-finite verb cannot generally serve as the main verb in an independent clause; rather, it heads a non-finite clause.

By some accounts, a non-finite verb acts simultaneously as a verb and as another part of speech; it can take adverbs and certain kinds of verb arguments, producing a verbal phrase (i.e., non-finite clause), and this phrase then plays a different role — usually noun, adjective, or adverb — in a greater clause. This is the reason for the term verbal; non-finite verbs have traditionally been classified as verbal nouns, verbal adjectives, or verbal adverbs.

English has three kinds of verbals: participles, which function as adjectives; gerunds, which function as nouns; and infinitives, which have noun-like, adjective-like, and adverb-like functions. Each of these is also used in various common constructs; for example, the past participle is used in forming the perfect aspect (to have done).

Other kinds of verbals, such as supines and gerundives, exist in other languages.

Example:

One day a crow finds a tasty piece of cheese. She picks it up, flaps her wings, and flies to a high branch of a tree to eat it.