1. a cupcake /home/from school / when/ she/ returned / her mother/ baked/./ 2. yesterday/he/ I/ me/ when/ was/ called/ running/./ 3. the / failed/start / of/ he / has / since / that/ times /exam/ year / three/ the/./

`1.` Her mother had baked a cupcake when she returned home from school.

`->` MĐ ( QKHT ) + when + MĐ ( QKĐ ) : Hành động xảy ra trước hành động khác

`->` MĐ QKHT : S + had + P2 ...

`->` MĐ QKĐ : S + V2/ed ...

`2.` I was running when he called me yesterday.

`->` MĐ ( QKTD ) + when + MĐ ( QKĐ ) : Hành động xảy ra, hành động khác xen vào

`->` MĐ QKTD : S + was/were + Ving ...

`->` MĐ QKĐ : S + V2/ed ...

`3.` He has failed that exam three times since the start of the year.

`->` HTHT : S + has/have + P2 ...

`->` DHNB : three times

`->` since + mốc thời gian

`->` Chủ ngữ số ít + has