1. knows
2. doesn't usually rain
3. usually wears, is wearing
4. does he usually read, doesn't read
5. is the teacher doing, is correcting
6. are you buying, have
7. usually drink, I'm drinking
8. is ringing, is calling
9. comes
10. always sing, isn't it singing
11. don't build
12. is Jake studying, he is studying
13. are you doing, I'm looking for
14. is waiting
15. doesn't smile
16. often spend
