1. is, writes, has already written
2. helps, have already washed and have dusted, are cooking
3. are they doing, are working, work
4. where is he, is, is playing, play
5. have you found, am still looking, do not remember, have put
6. have known, has always been
7. are you reading, am reading, have almost come, haven't understood
8. drinks, have always preferred
9. are, are still playing
10. has your father returned, has been