Collins Cobuild English Grammar (194 page)

The base form of a verb is the form that is used in the infinitive. It is the form that is given first in a dictionary where a verb is explained, and that is given in the lists in this grammar.

The
s
form of a verb consists of the base form with
s
on the end.

The
-ing
participle usually consists of the base form with
ing
on the end. It is sometimes called the
present participle
.

The past form of a verb usually consists of the base form with
ed
on the end.

In the case of regular verbs, the past form is used for the past tense and is also used as the
-ed
participle. It is sometimes called the past participle.

However, with many irregular verbs (see paragraph
R72
) there are two different forms:

a past tense form e.g.
stole

an
-ed
participle form e.g.
stolen

There are rules about the spelling of the different forms of verbs, depending on their endings. These are explained in paragraphs
R54
to
R70
.

Certain verbs, especially common ones, have irregular forms. These are listed in paragraphs
R72
to
R75
.

The forms of the auxiliaries
be
,
have
, and
do
are given in paragraph
R80
.

R53
    Each verb form has various uses.

The base form is used for the present tense, the imperative, and the infinitive, and is used after modals.

The
s
form is used for the third person singular of the present tense.

The
-ing
participle is used for progressive forms,
-ing
adjectives,
-ing
nouns, and some clauses.

The past form is used for the past simple, and for the
-ed
participle of regular verbs.

The
-ed
participle is used for perfect forms, passives,
-ed
adjectives, and some clauses.

R54
    The basic verb forms have been described in paragraph
R52
. The following paragraphs explain how the various forms of verbs are spelled. They also give details of verbs that have irregular forms. The forms of the auxiliaries
be
,
have
, and
do
are dealt with separately in paragraphs
R80
to
R88
.

R55
    The
s
form of most verbs consists of the base form of the verb with
s
added to the end.

sing		sings
write		writes

When the
s
follows one of the sounds
/f/
,
/k/
,
/p/
,
/t/
, or
/θ/
, it is pronounced
/s/
.

break		breaks
keep		keeps

When the
s
follows one of the sounds
/
S
/
,
/z/
, or
/ʤ/
, it is pronounced
/
I
z/
.

dance		dances
manage		manages

In most other cases the
s
is pronounced
/z/
.

leave		leaves
refer		refers

R56
    With verbs whose base form ends in a consonant letter followed by
y
, you substitute
ies
for
y
to form the
s
form.

try		tries
cry		cries