Dạng 1: S + have / has (not) + V3 / ed + phần phụ + since / for + thời gian

`1.` I bought these air-conditioners at the beginning of December

`=>` I have bought these air -conditioners since the beginning of December 

- Dạng 2: S + began / started / stopped + V-ing + phần phụ + thời gian có in / on / at / ago /when

1. She has learned French with foreigners since 2005

=> She started learning French with foreigners in 2005

2. My father hasn't planted trees in the garden for two months.

=> My father stopped planting trees in the garden two months ago 

3. My uncle has taught English for five years

=> My uncle began teaching English five years ago

4. They haven't produced this kind of toy for a long time

=> They stopped producing this kind of toy of a long time

5. Snow has dropped in this area since last December

=> Snow started dropping in the area last December 

6. It has not rained since this morning

=>It stopped raining this morning

7. The boys have played football since 2 o'clock

=> The boys began playing football at 2 o'clock 

8. Mr. Pike has worked for my boss for five years

=> Mr. Pike started working for my boos five years ago

9. This department store has provided us with cheese since last summer

=> This department store started providing us with cheese last summer