`\color{#145277}{N}\color{#246483}{a}\color{#34768F} {e}\color{#44889B}{u}\color{#539AA7}{n}`

`***` Thì HTHT : 

`@` For `+` quãng thời gian : trong khoảng (for a month, for a long time)

`@` IF `3` : IF + S + had + V3/ed

`@` Since `+` mốc thời gian : từ khi (since `2006`, since `2008`)

`(+):` S + have/ has + VpII

`(-):` S + have/ has + not + VpII

`(?):` Have/ Has + S + V3 `?`

       WH-word + have/ has + S (not) + V3 `?`

`->` S = I/ We/ You/ They + have

`->` S = He/ She/ It + has 

`@` For `+` quãng thời gian : trong khoảng (for a month, for a long time)

`@` Since `+` mốc thời gian : từ khi (since `2006`, since `2008`) / Since + V2

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

`bb\1.` S + started / began + V_ing / to – V + O + (time)

`->` S + have / has + V3 / ed +  O + since / for + time

`bb\2.` This is the first time + S + have / has + V3 / ed + O

`->` S + have / has + never + V3 / ed + O + before

`bb\3.` When did + S + V_bare + O `?`

`->` How long ago + did + S + V_bare + O `?`

`->` How long + have / has + S + V3 / ed + O `?`

`->` How long is it / has it been + since + S + V2 / ed + O `?`

`bb\4.` S +  have / has + V3 / ed +  O + for + time

`->` It is / It has been + (time) + since + S + V2 / ed + O

`-` S + have / has + not + V3 / ed +  O + for + time

`->` It is / It has been + (time) + since + S + last + V2 / ed + O

`bb\5.` The last time + S + V2 / ed  + O + was + (time)

`->` S + last + V2 / ed + O + (time)

`@` S + had + V3 / ed, before + S + V2 / ed

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

`1.` Tom has played the piano for `4` years.

`2.`  I have cooked for the party for `4` hours.

`3.` She has worked as a secretary for `2` years.

`4.` My father has been reading a newspaper for `2` hours.

`-` HTHT tiếp diễn : S + have / has + been + V_ing

`5.` My sister has studied English for a year.

`6.` Scientists have been fighting against AIDS in `1980.`

`-` HTHT tiếp diễn : S + have / has + been + V_ing

`7.` The Browns began to live in London `20` years ago.

`8.` John started working for this electronics firm in `1999.`

`9.` Women began to fight for their rights in the middle of the `20th` century.

`10.` Jack and Bill started learning to drive `2` weeks ago.

`11.` When did you study English `?`

`12.` How long is it since you did research on lung cancer `?`

`13.` The last time I met her was `2` months ago.