`II.`
1. did
2. has written - hasn't finished
3. left - never haven't met
4. have - had
5. did - do - played
6. bought - hasn't worn
7. has taught- graduated
8. Have - heard - has been - Have - read
9. got - was - went
10. earned- has already spent.
`=>` Giải thích:
- Công thức thì quá khứ đơn:
+ Đối với động từ thường:
(+) S+ `V_2`/V-ed + O...
(-) S+ didn't + V-inf + O...
(?) Did + S+ V-inf+ O...?
+ Đối với động từ tobe:
(+) S+ was/were+O....
(-) S+ was/were+ not + O....
(?) Was/were+ S+O...?
+ Dấu hiệu nhận biết: last night, 10 years ago,.... (hoặc mệnh đề đứng sau "since" )
- Công thức thì hiện tại hoàn thành:
(+) S+ has/have+ `V_3`/V-ed+O....
(-) S+ hasn't/haven't +`V_3`/V-ed+O..
(?) Have/Has+ S+ `V_3`/V-ed+O...?
- Dấu hiệu nhận biết: for 2 years, already, yet, ... (hoặc mệnh đề đứng trước "since")
$@thubui$