1.When you phoned me,it was my lunchtime.
-> When you phoned me, I was having lunch

2. Jack left the office before I arrived there. 

-> When I arrived at the office, Jack had left

3. I have studied English for three years.

-> We started to study English for three years.

4. Sue cleaned the house. Then she fell asleep on the sofa.

-> After Sue had cleaned the house, she felt asleep on the sofa. 

5. Brian bought a new television. First she checked all the prices.

-> Before Brian bought a new television, he had checked all the prices

Công thức câu 4 với câu 5 nè:

• After + S+ had V3/ V-ed

• Before= by the time + S+ V2/ V-ed

CHO MÌNH CÂU TRẢ LỜI HAY NHẤT NHAAAA

1 when you phoned me i was having lunch

→ thì QKTD : s + was / were + V-ing

→ QKĐ + when + QKTD

2 when i arrived jack had left the office

→ thì QKHT : s + had + VPII

3 i started studying english 5 years ago

→ thì QKĐ ; S  v-ed / v2

4  after sue had cleaned the house  she felt asleep on the sofa

→ thì QKHT : s + had + VPII

5 before bought a new television she had checked all the prices

→ thì QKHT : s + had + VPII