Change the verb into the correct form:
1. I (work) too much, so I (take) a vacation.
2. They (play) basketball before they (switch) to baseball.
3. She (sell) soaps before she (open) her own company.
4. We (expect) her when she (arrive).
5. When Joe (arrive), Bill (wait) for over an hour.
6. Sheila (be) very sad because she (fight) with her boyfriend.
7. George (be) very excited because he (wait) to invite Sheila to the movies.
8. Patricia (feel) sick because she (eat) several burgers.
9. You (buy) the food before you (cook) it.
10. I (run) for 2 hours by the time I (get) really tired.
11. I (notice) that somebody (smoke) there.
12. They (say) that they (work) very hard.
14. Trevor (date) a lot before he (meet) his wife.
15. I (visit) many places before I (arrive).