Since 用來說明動(dòng)作起始時(shí)間，for用來說明動(dòng)作延續(xù)時(shí)間長(zhǎng)度。
I have lived here for more than twenty years.
I have lived here since I was born..
My aunt has worked in a clinic since 1949.
Some new oilfields have been opened up since 1976.
I have known Xiao Li since she was a little girl.
My brother has been in the Youth League for two years.
I have not heard from my uncle for a long time.
注意：并非有for 作為時(shí)間狀語的句子都用現(xiàn)在完成時(shí)。
I worked here for more than twenty years.
(我現(xiàn)在已不在這里工作。)
I have worked here for many years.
(現(xiàn)在我仍在這里工作。)
小竅門：當(dāng)現(xiàn)在完成時(shí)+一段時(shí)間，這一結(jié)構(gòu)中，我們用下面的公式轉(zhuǎn)化，很容易就能排除非延續(xù)動(dòng)詞在完成時(shí)中的誤使。
1)(對(duì)) Tom has studied Russian for three years.
= Tom began to study Russian three years ago, and is still studying it now.
2)(錯(cuò)) Harry has got married for six years.
= Harry began to get married six years ago, and is still getting married now.
顯然，第二句不對(duì)，它應(yīng)改為 Harry got married six years ago.或 Harry has been married for six years.
Since 用來說明動(dòng)作起始時(shí)間，for用來說明動(dòng)作延續(xù)時(shí)間長(zhǎng)度。
I have lived here for more than twenty years.
I have lived here since I was born..
My aunt has worked in a clinic since 1949.
Some new oilfields have been opened up since 1976.
I have known Xiao Li since she was a little girl.
My brother has been in the Youth League for two years.
I have not heard from my uncle for a long time.
注意：并非有for 作為時(shí)間狀語的句子都用現(xiàn)在完成時(shí)。
I worked here for more than twenty years.
(我現(xiàn)在已不在這里工作。)
I have worked here for many years.
(現(xiàn)在我仍在這里工作。)
小竅門：當(dāng)現(xiàn)在完成時(shí)+一段時(shí)間，這一結(jié)構(gòu)中，我們用下面的公式轉(zhuǎn)化，很容易就能排除非延續(xù)動(dòng)詞在完成時(shí)中的誤使。
1)(對(duì)) Tom has studied Russian for three years.
= Tom began to study Russian three years ago, and is still studying it now.
2)(錯(cuò)) Harry has got married for six years.
= Harry began to get married six years ago, and is still getting married now.
顯然，第二句不對(duì)，它應(yīng)改為 Harry got married six years ago.或 Harry has been married for six years.
