2. Every sentence has a subject and a verb
and the subject and the verb must agree in
number.
3. In the sentences like ,
The child laughs at the clown.
The children laugh at the clown.
The verb in sentence (i), the subject is
‘laughs’ is a singular verb because the
subject ‘child’ is a singular subject.
4. In the sentence (ii), the subject is
‘children’ which is a plural noun and
so the verb also changes to a plural
verb ‘laugh’.
To understand better there is a vedio.