Question

1.she said that she(can't/couldn't) come to the party.
2. I knew that he(is/was) a very clever man.
3.he said that they (were/had been) friends at school some years before
4.i asked my sister what she(has bought/had bought) for my birthday

Answer 1

1. второе
2.первое
3.первое
4.второе.