7. c you, we и they используется were. в остальных случиях was.
1) where were they ....
Harry was at home ... Sally and Mike were..
2)where were you.....we were....John was.
3)were you...I was't.. l was.
4) was the book.....it was
5) was. ....were
6) was .... it wasn't. it was
7)were... weren't. ..were