Grammar · Agreement
Making the verb match its subject
Subject–verb agreement means choosing the verb form that fits the subject. The trickiest part is the -s rule: a singular subject takes a verb with -s (the cat sits), while a plural subject takes the verb without -s (the cats sit). You also need the right forms of 'to be' and care with two subjects or in-between words. Learn each below.
1 The verb must match its subject
Subject–verb agreement means the verb form fits the subject — one thing or more than one.
The dog runs. (one) · The dogs run. (more than one) ✓
2 The tricky -s rule
In the present tense, a singular subject usually takes a verb with -s; a plural subject takes the verb with no -s.
She walks. / They walk. · The cat sleeps. / The cats sleep. ✓
Careful: this feels backwards — the -s goes on the verb for ONE, not for many.
4 Two subjects joined by 'and'
Two subjects joined by and are plural, so they take the plural verb.
Tom and Sam are here. · My brother and I were late. ✓
Watch out Words between subject and verb
Ignore words that come between the subject and verb — match the verb to the real subject.
The box of toys is heavy. (subject = box, not toys) ✓
10 worked examples
Read the question, then the answer with the rule that solves it.
1. The bird ___ (sing/sings).
sings — one subject takes -s (Rule 2).
2. The birds ___ (sing/sings).
sing — plural, no -s (Rule 2).
3. She ___ (is/are) tall.
is — 'she' is singular (Rule 3).
4. They ___ (was/were) happy.
were — 'they' is plural (Rule 3).
5. Tom and Ben ___ (is/are) friends.
are — two subjects = plural (Rule 4).
6. I ___ (am/is) ready.
am — 'I' takes 'am' (Rule 3).
7. The box of apples ___ (is/are) heavy.
is — subject is 'box', singular (Watch out).
8. My friends ___ (likes/like) games.
like — plural, no -s (Rule 2).
9. He ___ (do/does) his best.
does — singular takes -s (Rule 2).
10. We ___ (was/were) at the park.
were — 'we' is plural (Rule 3).