$1. $ Last year, we started the community garden project

$→$ Thì QKĐ : S + Ved/V2

$→$ Dấu hiệu : last year

$2. $ So far we have asked people to donate books and clothes to the poor children

$→$ Thì HTHT : S + have/has + Vpp

$→$ Dấu hiệu : so far

$→$ Donate (v) : Quyên góp

$3. $ Because the lake was full rubbish, they decided to clean it up last Sunday

$→$ Thì QKĐ : S + Ved/V2

$→$ Thì QKĐ với động từ tobe : S + was/were + ...

$→$ Dấu hiệu : last sunday

$→$ Because dùng để chỉ nguyên nhân của sự việc, hành động

$4. $ Green summer was organized first time in 1997

$→$ Câu bị động thì QKĐ : S + was/were + Vpp + (by O)

$→$ Dấu hiệu : in 1997

$5. $ Go Green is a non-profit organisation that protects the environment

$→$ Thì HTĐ với động từ tobe : S + am/is/are + N/adj

$6. $ When did you start to work for this charitable organization ?

$→$ Thì QKĐ dạng nghi vấn : Wh-question + did + S + V-bare ?

1. lasr year/ we / start/ community garden/ project .

→ Last year we started the community garden project.

2. so far/ we/ ask/ people/ donate/ books and clothes/ the poor children .

→So far we have asked people to donate books and clothes to the poor children.

3 . because / the lake/ be/full/ rubbish/they/decide/clean it up/ last Sunday.

→ Because the lake was full rubbish, they decided to clean it up last Sunday.

4. Green Summer/organize/ first time/in1997.

→Green Summer has organized first time in 1997.

5. Go Green/non-profit/organisation/that/protect/environment.

Go Green is a non-profit organisation that protects the environment.

6. when/you/start/work/this charitable organization ?

→When did you start to work for this charitable organization?