`1.` fishing - is ( Form: fancy + V_ing )

`2.` has collected - was ( HTHT - since: S + have/has + Vp.p + .. )

`3.` have studied ( HTHT - for two years )

`4.` will have stayed ( TLHT - for a few day next week, nếu bỏ "next week" thì đáp án sẽ khác )

`5.` will be having ( TLTD - at this time tomorrow )

`6.`  will be used ( câu bị động TLĐ - in the future ) 

`7.` sitting ( Form: advoid + V_ing )

`8.` needs ( câu điều kiện loại 0 ) 

1/ fishing ( sau fancy + V-ing ) - is 

2/ has collected ( HTHT ; dấu hiệu : since ) - was 

3/ have studied ( HTHT ; dấu hiệu : for )

4/ will stay ( TLĐ ; dấu hiệu : next week )

5/ are going to have ( TLG ; dấu hiệu : at this time tommorrow )

6/ will use ( TLĐ ; dấu hiệu : in the future )

7/ sitting ( sau avoid + V-ing )

8/ will need ( câu điều kiện loại 1 )