1. knows, doesnt know
2. It is raining.
3. drinks, is drinking
4. have lost
5. have been writing, have already finished
6. Have you ever been to China No, I havent, but Ive been to Japan twice.
7. have been typing, have already typed
8. has been making, How many cakes has she made
9. Fred often writes the letters to his friend, doesnt he
10. has been translating
11. Where do you usually spend your weekend
12. Who is playing computer games now Sam and Bob are.
13. What language does Mr Brown teach at the institute
14. have walked, have been walking
15. has broken