`1.` was playing

`@` Cấu trúc: While `+` S `+` V(QKTD), S `+` V(QKTD)

`->` Diễn tả hai hành động xảy ra đồng thời, song song trong quá khứ.

`->` QKTD: S `+` was/were `+` V-ing

`->` QKĐ: S `+` V2/ed

`2.` have worked `-` graduted

`@` Cấu trúc: S `+` V(HTHT) `+` since `+` S `+` V(QKĐ)

`->` HTHT: S `+` have/has `+` PII

`->` QKĐ: S `+` V2/ed

`3.` had `-` had written

`@` Cấu trúc: Before `+` S `+` V(QKĐ), S `+` V(QKHT)

`->` QKHT: S `+` had `+` PII

`->` QKĐ: S `+` V2/ed

`4.` went `-` had finished

`@` Cấu trúc: After `+` S `+` V(QKHT), S `+` V(QKĐ)

`->` QKHT: S `+` had `+` PII

`->` QKĐ: S `+` V2/ed

`1.` was playing

`-` CT: S + was/were + V-ing + while + S + was/were + V-ing

`->` Diễn tả hai hành động cùng song song diễn ra trong quá khứ

`2.` have worked - graduated

`-` DHNB: since + S + Ved/c2 `->` Vế sau dùng thì QKĐ

`-` Form `(+)`: S + Ved/c2

`->` Có DHNB dùng thì HTHT

`-` Form `(+)`: S + have/has + Vpp

`-` CN là 'I' `->` Dùng 'have'

`3.` had - had written

`-` CT: After + S + had + Vpp, S + Ved/c2 = Before + S + Ved/c2, S + had + Vpp

`->` Diễn tả một hành động diễn ra trước 1 hành động khác trong quá khứ, dùng thì QKHT

`-` Form `(+)`: S + had + Vpp

`4.` went - had finished