Use the verb "to be" either in Present Simple or in

1. They are 10 today. (Present Simple)

2. Where is John? I want to see him. (Present Simple)

3. Ben was 7 yesterday. (Past Simple)

4. Where were you last month? (Past Simple)

5. Sam is not in London now. (Present Simple)

6. Fred was in the park last week. (Past Simple)

7. We are at home today. (Present Simple)

8. Who was at school yesterday? (Past Simple)

9. Bob and I are singing now. (Present Simple)

10. With whom was your sister at the Zoo last week? (Past Simple)