Finite & Non-Finite verbs
A finite verb (sometimes called main verbs) is a verb that has a subject, this means that it can be the main verb in a sentence. It shows tense (past / present etc) or number (singular / plural).
・I go to the market.
・He goes to the market.
・She went to the market.
In verb phrases, it is the auxiliary verb that is the finite verb.
・He is going to the market.
・They are going to the market.
Although modal auxiliary verbs are finite verbs and change to indicate reference to the past, the present or the future, they don't, unlike other finite verbs, change in form to agree with their subject.
・They can go tomorrow.
・They could not go last week.
Verbs that express wishes or commands are also considered finite verb, even though, they don't change in form to agree with their subject, and infect usually don't have a subject expressed in the sentence at all.
・Don't touch him.
Non-infinite verbs don't change in form to agree with a subject, or to indicate past,present and future.
As a result, a non-finite verb cannot serve as a predicate and can be used in anindependent clause only when combined with an auxiliary verb.
・He is working hard.
・I am working hard.
・He was working hard.
An infinitive need not always follow an auxiliary verbs, it may also follow a lexical verb. But note that while an auxiliary verb is followed by a bare infinitive (V1), a lexical verb is usually followed by a to + bare infinitive. But lexical verb 'let' always followed by bare infinitive (V1).
・He will come with us.
・He wants to come with us.
・Let them come in.
Adjective and nouns are sometimes followed by to + V1
・I am very glad to see you.
・It is time to take tea.
・Nice to meet you.
Kinds of non-finite Verb
Infinitives are often used after other verbs. A modal verb is followed by a bare infinitiveand a lexical verb is followed by to infinitive:
・We can go.
・We want to go.
・They like to sing.
Gerund (Verbal Noun)
Verbal nouns or gerunds have the same form as present participles, but behave as nouns rather than verbs. For example, a gerund can act as the subject or object in a sentence:
・Playing football is good for you.
・I hate telling lies.
A participle is a verbal adjective that describes a noun as being a participant in the action of the verb.
English has two kinds of participles:
1. A present participle, also called an imperfect participle, which ends in -ing and which ordinarily describes the agent of an action.
2. A past participle, also called a perfect participle, which typically ends in -ed (but can also end in -en, -t, or none of these), and which ordinarily describes the patient of an action.
・The talking children angered the teacher.
(Here talking modifies children.)
・Annoyed, Rita ate dinner by herself in the bedroom.
(Here annoyed modifies Rita.)
・Jim was sleeping.
・Let sleeping dogs lie
・The chicken has eaten.
・The chicken was eaten.
・I am coming.
・I have gone.
・He was caught.