Ответ:

1.

1) wasn't

2) bought

3)didn't

4)did

5) started

a. irregular - bought. остальные regular.

b. добавляем окончание ed.

c. did, was.

2.

1) were

2) was

3) was

4) were

5) weren't

6) were

7) were

8) was

9) wasn't

10) was