时态since 和for 的比较

Since 用来说明动作起始时间，for用来说明动作延续时间长度。

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.

I worked here for more than twenty years.

(我现在已不在这里工作。)

I have worked here for many years.

(现在我仍在这里工作。)

1) (对) Tom has studied Russian for three years.

= Tom began to study Russian three years ago, and is still studying it now.

2) (错) Harry has got married for six years.

= Harry began to get married six years ago, and is still getting married now.

显然，第二句不对，它应改为 Harry got married six years ago.

或 Harry has been married for six years.