`1.` We have moved into the new house since last month.

`2.` They have worked on this project for two months.

`3.` Mary has learnt to play the piano since her childhood.

`4.` He has joined the company for two years.

`-------------`

`-` Biến đổi Hiện tại hoàn thành `<=>` Quá khứ đơn

`1)` S + haven’t/hasn’t + Ved/ PII + since/for + time

`=` S + last + Ved/V2 + time

`=` The last time + S + Ved/V2 + was + time

`2)` S + have/has + Ved/ PII + since/for + time

`=` S + started/began + to V/V-ing + time

`3)` When + did + S + V?

`=` How long + have/has + S + Ved/ PII?

`4)` It/This is the first time + S + have/has + (ever) + Ved/ PII

`=` S + haven’t/hasn’t + Ved/PII + before

`=` S + have/has + never + Ved/PII + before

`5)` S + haven’t/hasn’t + Ved/PII + since/for + time

`=` It is/It has been + time + since + S + last + Ved/V2