Verb forms and agreement

The idea

Many common verbs are irregular: their past forms do not just add '-ed'. You have to learn them, such as 'swim, swam', 'write, wrote' and 'choose, chose'. Using the present form, or inventing 'swimmed', will lose the mark.

After 'has', 'have' or 'had' you need the past participle, which is sometimes different again: 'she has written', 'they have chosen', 'he has swum'. A good test is to say the verb in the frame 'I have ___' and check it sounds right.

Agreement matters too: the verb must match its subject. A singular subject takes a singular verb — 'the dog barks' — and a plural subject takes a plural verb — 'the dogs bark'. Take care when other words sit between the subject and the verb.

Worked example

Complete the sentence with the correct forms of 'swim' and 'write': Yesterday, Priya ___ across the lake, and this morning she has ___ a report about it.

1. 'Yesterday' signals the simple past tense. The past tense of 'swim' is the irregular form 'swam'.
2. After 'has' you need the past participle. The past participle of 'write' is 'written' (write, wrote, written).
3. Check agreement: 'she' is singular, so 'has' is correct.

Answer: Yesterday, Priya swam across the lake, and this morning she has written a report about it.

Watch out

• Adding '-ed' to irregular verbs, giving forms like 'swimmed' or 'writed'.
• Using the simple past after 'has', as in 'she has wrote' instead of 'she has written'.