3) are you doing; have been waiting
4) won't be writing; will already have written
5) are you doing; am preparing; have you been preparing
6) had been waiting; saw
7) would read
8) came; had already returned; was sitting
9) comes; will have still packing
10) writes; has been writing; has already written
11) has been waiting; would ring
12) will have translated
13) have you ever spent; have; was
14) will he do; finishes; will enter
15) did you see; saw
16) have done
17) will have worked
18) were you reading
19) did you learn; am still learning; have already been learning; haven't learnt it yet
20) had been raining
