before當連詞和介詞分別放在什么位置？

before作連詞,是從屬連詞連接時間狀語從句,

在...之前,與after相反.例如：

*He had been a soldier for three years before he came to our city .

*She had learnt 2000 English words before she went to the USA.

before 作介詞,分三種：

1）表時間,這和上面相似.

*She left the office before 9 o'clock.

*I finished studying English before midnight.

區別就是:連詞+從句；介詞+名詞.

2）表順序,第一、第二、...,也與after相反

*ZhangHong goes before me.

*There are five man before her.

3)表位置,（較不常用）也與after相反

*The car stops before my house.

*The tall tree stands before our school gate.

一般英語里用in front of...\behind...來表示位置的前后.

*The car stops in front of my house.

*The tall tree stands in front of our school gate.