`1,`

`@` have you bought it?

`@` did you buy it?

`@` since you bought it?

`@` been since you bought it?

`2,`

`@` you come here?

`@` did you come here?

`@` since you came here?

`@` been since you came here?

`3,`

`@` you learned English?

`@` did you start learning English?

`@` since you learned English?

`@` been since you learned English?

`4,`

`@` you worked in this factory?

`@` did you start working in this factory?

`@` since you worked in this factory?

`@` been since you worked in this factory?

`5,`

`@` you first met him?

`@` did you first meet him?

`@` since you first met him?

`@` been since you first met him?

`6,`

`@` they got married?

`@` did they get married?

`@` since they got married?

`@` been since they got married?

`**` Quá khứ đơn - Hiện tại hoàn thành :

- When + did + S + V nguyên thể : ai đó làm gì khi nào?

`->` When = How long ago `=>` How long ago + did + S + V nguyên thể?

`->` How long + have/has + S + PII : ai đó làm gì được bao lâu rồi?

`->` How long is it/ has it been + since + S + V (quá khứ đơn) : đã bao lâu kể từ khi ai đó làm gì?

- When + did + S + start/ begin + to V/ V-ing : ai đó bắt đầu làm gì khi nào?

`->` When = How long ago `=>` How long ago + did + S + start/ begin + to V/ V-ing?

`->` How long + have/has + S + PII : ai đó làm gì được bao lâu rồi? (bỏ "start/ begin")

`->` How long is it/ has it been + since + S + V (quá khứ đơn) : đã bao lâu kể từ khi ai đó làm gì? (bỏ "start/ begin")