1. was swimming/saw

-> Cấu trúc: Thì QKTD + when + Thì QKĐ

2. didn't go

-> "yesterday" => Thì QKĐ

3. has begun

-> "already" => Thì HTHT

4. Did ... watch ...

-> "ago" => Thì QKĐ

5. lived

-> HĐ "live" đã xảy ra và kết thúc trong QK "from 1990 to 2000" => Thì QKĐ

6. got/had eaten 

-> Cấu trúc "By the time" với thì QK: By the time + `S_1` + V_ed/V_pI, `S_2` + had + V_ed/V_pII

7. were ... doing ...

-> "at this time last week" => Thì QKTD 

8. felt/was watching

-> Cấu trúc: Thì QKĐ + while + Thì QKTD: HĐ ở mệnh đề while đang diễn ra thì HĐ còn lại chên vào

9. was/worked

-> "yesterday" => Thì QKĐ

10. has .... finished

-> "already" => Thì HTHT

#Chii

#Tired of studying well

1 was swimming - saw ( HĐ dài xảy ra bị HĐ khác cắt ngang: HĐ dài : be + Ving , HĐ ngắn V)

2 didn't go ( yesterday dùng QKĐ)

3 had- begun ( xảy ra trc sự viêc trg QK là QKHT: S + had + V3/ed)

4 Did - watch ( ago+ QKĐ)

5 lived ( thời gian trg qk dùng QKĐ)

6 got - had eaten ( xảy ra trc sự viêc trg QK là QKHT: S + had + V3/ed)

7 were- doing ( time + QK -> QKTD: S+ was/were Ving)

8 fell - was watching ( HĐ dài xảy ra bị HĐ khác cắt ngang: HĐ dài : be + Ving , HĐ ngắn V)

9 was - had worked  (xảy ra trc sự viêc trg QK là QKHT: S + had + V3/ed)

10 had - finished ( tường thuật lùi thì)