英语六级语法精要：since和for的用法

 　　since¹和for的用法：

　　since 用来说明动作起始时间，for用来说明动作延续时间长度;

　　eg：I have lived here for more than twenty years.

　　I have lived here since I was² born³.

　　for后面多接一段时间，而since后面则接一个时间点，若since后面也出现时间段，则在时间段后加ago;

　　eg： I have lived here since twenty years ago.

　　错句：I have worked here since many years.

　　since句型：

　　It is +一段时间+ since从句，since从句要用一般过去时;

　　eg：It is two years since I became⁴ a postgraduate⁵ student.

　　It is three years since I joined the army⁶.

1 since   

adv.后来；conj.既然，因为，自从；prep.自从

参考例句：

• He's been working in a bank since leaving school.自从毕业后，他就一直在一家银行工作。
• I have known him ever since I was a child.我自孩提时代起就已经认识他了。

2 was   

v.(is,am的过去式)是，在

参考例句：

• He said he was right.他说他是正确的。
• He was cold and hungry.他又冷又饿。

3 born   

v.动词bear的过去分词；adj.出生的，与生俱来的

参考例句：

• The baby can cry as soon as he is born.婴儿生下来就会哭。
• I feel as if I had been born again.我有一种再生之感。

4 became   

v.(become的过去式)成为

参考例句：

• He became a doctor at the age of 27.他27岁时成了一名医生。
• He became a millionaire when he was still young.他还年轻时就成了百万富翁。

5 postgraduate   

adj.大学毕业后的，大学研究院的；n.研究生

参考例句：

• I didn't put down that I had postgraduate degree.我没有写上我有硕士学位。
• After college,Mary hopes to do postgraduate work in law school.大学毕业后， 玛丽想在法学院从事研究工作。

6 army   

n.军队，陆军，正规军，野战军

参考例句：

• The army numbered four to five thousand at the start.这支军队开始才有四五千人。
• What is the total strength of the enemy army?敌军人数总共有多少？