【—since与for的】since与for是英语中经常需要同学们辨别的一词，下面就是老师为同学们带来的相关介绍。

　　Since 用来说明动作起始时间，for用来说明动作延续时间长度。

　　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。)

　　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.

　　对于since与for的比较，同学们看完之后是否已经知道了他们的区别呢？

本文来自：逍遥右脑记忆 http://www.jiyifa.com/chuzhong/210088.html

相关阅读：有关非谓语动词的重要考点