*Công thức chung:

`-`Qúa Khứ Tiếp Diễn+While+Qúa Khứ Tiếp Diễn

`-`Qúa Khứ Đơn+While+Qúa Khứ Tiếp Diễn(Một số trường hợp đặc biệt)

`-`Qúa Khứ Tiếp Diễn+While+Qúa Khứ Đơn

`-`Qúa Khứ Đơn+ago/Time(qk)

`1`.Fell/Was painting.   

`2`.Was reading/Heard

`3`.Were you watching/Phoned

`4`.Was waiting/Arrived

`5`.Was cleaning/Asked

`6`.Cost(Cost-Cost-Cost)

`7`.Was still burning

$\text{(Qúa Khứ Tiếp Diễn với thời gian xác định:at six)}$

`8`.Got

`9`.Discovered

`10`.Was/Didn't understand

$\text{(Hành động ''không quan tâm'' đã là trong quá khứ)}$

$\text{@TriLeCongTri}$

$\text{chúc em học tốt!!!!!!!}$

cấu trúc: past simple + while+ past continuous

                when + past continuous + simple past.

1 fell, was painting.   

2 was reading, heard

3. You were watching, phoned

4. was waiting, arrived

5. was cleaning, asked

6. cost

7. still burning.

8. got (ago - qkhu don)

9. was discovered ( bi dong )

10. is, doesn't