Ответ:

1.) We came home at 12 o'clock yesterday.

When did we come home at yesterday?

We didn't came home at 12 o'clock yesterday.

2.) Her little sister went to school last year.

When did her little sister go to school?

Her little sister didn't go to school last year.

3.) My father drove a car last Sunday.

When did my father drive a car?

My father didn't drive a car last Sunday.

4.) I saw him yesterday.

When did I see him?

I didn't see him yesterday.

5.) Carol bought her new coat yesterday.

When did Carol buy her new coat?

Carol didn't buy her new coat yesterday.

6.) They had dinner an hour ago.

When had they have dinner?

They hadn't have dinner an hour ago.

7.) She was at home yesterday.

When was she at home?

She wasn't at home yesterday.