Question

Correct the following sentences and rewrite them.
One of the boy was 12 years old.
When did you came?​

Answer 1

Answer:

One of the boys was 12 years old.

When did you come?

Answer 2

Answer:

1. One of the boys was 12 years old.

2. When did you come?

Explanation:

Boys because he is among many of them.

Error of double past tense- did and came.

3. I have bought a pair of trouser.

Answer: I have bought a pair of trousers.

There is no word Trouser in English. Trousers pants, scissors, etc are always in the plural form.