1: caused
2: are going to see ( thì HTTD )
3: speak ( can/could/should/have/... + V - infi )
4: wrote ( thì QKĐ )
5: did.....learn.....teached ( thì QKĐ )
6: go.....went ( thì HTĐ và QKĐ )
7: introduced ( QKĐ )
8: was.....didn't have ( QHĐ )
9: will.....do.....will visit ( TLĐ )
10: to come ( Would ... to + V-infi )
11: playing ( enjoy,like,love,... + V-ing )
12: to go ( enough + to + V-infi )
13: received ( QKĐ )
14: to go ( Would ... to V-infi )
15: did.....spend ( QKĐ )
16: came ( QKĐ )
17: are playing ( HTTD )
18: won't go ( TLĐ )
19: teached ( QKĐ )
20: is taking ( HTTD )