英语在现代生活中是不可或缺的，每年的AEIS考试中都会有广大考试为英语皱眉。这次我们的AEIS培训老师为大家提升的AEIS考点是定比较状语从句。

than, as as ，not so as ， the same as, the+比较级;

eg：Light travels fast than sound.

the+比较级：

eg：The sooner，the better.

eg：Girls are thus seen as less valuable than boys and art kept at home to do housework while their brothers are sent to school - the prophecy becomes self- fulfilling, trapping women in a vicious circle of neglect.

当 的时候：while, when, as ;

when：强调一件事情正在发生的时候，另外一件事情突然发生;

eg：When I was watching TV, my mother came back.

while：强调两个动作同时进行，一边 一边 ;

eg：My father is cooking while my mother is reading newspaper.

as： 随时间推移

eg：As time went by, the days became longer and longer.

一 就 ：as soon as ,主将从现;用directly，immediately, instantly连接两个句子;一些名词如the minute，the moment, the instant也可表示;no sooner than, hardly when后面的句子需要倒装;

eg：I will write to you the moment/minute I arrived in Paris.

特殊单词：by the time that, every/each time

till until：

① 肯定形式表示的意思是 做某事直至某时 ，动词必须是延续性的;

否定形式表达的意思是 直至某时才做某事 ，一般用until，动词为延续性或非延续性都可以;

eg: I slept until midnight.

Wait till I call you.

She didn t arrive until 6 o clock.

② Until可用于句首，而till通常不用于句首，通常用于句中;

eg: Until you told me, I had heard nothing of what happened.

eg：As you sleep you pass through a sequence of sleep states light sleep, deep sleep and REM sleep that repeats approximately every 90 minutes.