Verb forms and finiteness in English

Old version (Fall 2006) - current version here

Verb forms

Verbs in English can take the various forms listed in (1)-(5).

Name Description Examples

(1)     Bare Default form in present tense sentences. They play together.
I see.
Also appears in various nonfinite contexts, such as in to infinitive clauses, I want to play.
They need to see you.
after modals, They may play.
We will see.
and in connection with do support. They don't play lacrosse.
Do you see?

(2)     -s Special form used in the present tense to mark agreement with a third person singular subject. Lukas runs for miles.
The cat enjoys treats.

(3)     -ing As present participle, combines with auxiliary be to express various aspectual nuances The cat is playing with the yarn.
I was seeing her until a week ago.
Also occurs on its own as the gerund. Playing with landmines is dangerous.
We always enjoy seeing you.

(4)     -ed (past tense) Expresses past tense. The cat played with the yarn.
We saw a deer.

(5)     -en (past participle) Combines with auxiliary be to form passive forms. Baseball is played all over the world.
She was last seen off Mozambique.
Combines with auxiliary have to form perfect forms. They have never played lacrosse.
I have seen it many times.

For all verbs, the -ing form is predictable from the bare form, being derived from it by the affixation of -ing (play-ing, see-ing, hav-ing, be-ing). The -s form is similarly predictable for most verbs, with major (be, is) or minor (have, has) exceptions. The past tense and past participle forms are predictable from the bare form in some cases, but not in others. With regular verbs, the past tense and past participle forms are homonyms and are formed by affixing -ed to the bare form. Why bother distinguishing between the two forms? That is, why not just post a single past form? The reason is that the past tense and the past participle are distinct for irregular verbs such as go, see, sing, or write (past tense went, saw, sang, wrote versus past participle gone, seen, sung, written).

A verb's bare form, past tense, and past participle (in other words, exactly the forms that aren't predictable in general) are known as its principal parts.


The verb forms just discussed are classified into two categories: finite and nonfinite. The basic difference between the two categories in English is that finite verbs can function on their own as the core of an independent sentence, whereas nonfinite verbs cannot. Rather, nonfinite verbs must ordinarily combine with a modal, an auxiliary verb, or the infinitival particle to.

A verb's -s form and past tense form are always finite, and the two participles (the -ing and -en forms) are always nonfinite.

(6) a. Finite verb: ok She gives both of them a back rub.
b. ok She gave both of them a back rub.
(7) a. Nonfinite verb: ok She is giving both of them a back rub.
b. ok She has given both of them a back rub.

To complicate matters a bit, a verb's bare form can be either finite or nonfinite. Bare forms that express the present tense are finite; otherwise, they are nonfinite. Examples are given in (8) and (9).

(8)   Finite verb: ok We give both of them a back rub.
(9) a. Nonfinite verb: ok We will give both of them a back rub.
b. ok We promised to give both of them a back rub.

The finite character of a bare form that expresses the present tense fits with the following fact. When the subject in (8) is replaced by a third-person singular subject, as in (10), the bare form of the verb becomes ungrammatical and needs to be replaced by the -s form.

(10) a. * She give both of them a back rub.
b. ok She gives both of them a back rub.

Since the -s form is finite, it is sensible to classify the functionally equivalent bare form the same way.

Summary: Correlation between verb form and finiteness

Verb form Example Finite? present tense play-s, see-s yes
Past tense play-ed, saw "
Bare (present tense) play, see "

Bare (otherwise) play, see no
Present participle play-ing, see-ing "
Past participle play-ed, se-en "