* Quá khứ đơn (Past Simple Tense)
Công thức
(+) S + V_ed + C
(-) S + didn't + V + C
(?) Did + S + V + C?
Egs:
(+) I visited my grandparents last year
(-) She didn't collect stamps in 2016
(?) Did your mother make craft?
* Hiện tại hoàn thành (Present Perfect Tense)
Công thức:
(+) S + have/has + V_ed/P.P + C
(-) S + haven't/hasn't + V_ed/P.P + C
(?) Have/Has + S + V_ed/P.P + C?
Egs:
(+) I have eaten seafood since last night
(-) He hasn't done his homework.
(?) Have you learned English before?
Study well