上海酷学酷玩夏令营讲解英语语法：since和for的区别

上海酷学酷玩夏令营介绍，since 用来说明动作起始时间，for用来说明动作延续时间长度。

since和for的区别：

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 作为时间状语的句子都用现在完成时。

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。)

上海新东方夏令营提示，小窍门：　当现在完成时+一段时间，这一结构中，我们用下面的公式转化，很容易就能排除非延续动词在完成时中的误使。

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.