1. How long is it since you sold that car? à When _____________________________________________? 2. How long is it since you last saw her? à When _____________________________________________? 3. How long is it since you ate some meat? à When _____________________________________________? 4. How long have you worked as a waiter here? à When _________________________

`1.`When did you sell that car?

`-`Bạn đã bán chiếc xe đó khi nào?

`2.`When did you see Tom?

`-`Bạn nhìn thấy Tom khi nào?

`3.`When did you eat some meat?

`-`Khi nào bạn ăn một ít thịt?

`4.`When did you work as a waiter here?

`-`Bạn làm bồi bàn/phục vụ ở đây khi nào?

`->` Cấu trúc: When + did + S + V-inf + O? => How long is it + since + S(last) + V-ed + O?

`1.` When did you sell that car?

`2.` When did you see Tom?

`3.` When did you eat some meat?

`4.` When did you work as a waiter here?

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`-` Cấu trúc câu gốc chung: How long is it + since + S + last + Ved/Vc2 + .. 

=> Câu chuyển: When + did + S + V-inf + ..?