than, as…as…，not so as…，（not) the same as, the+比较级；
eg：Light travels fast than sound.
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（预言) becomes self- fulfilling, trapping women in a vicious circle (恶性循环) of neglect.
（1）当……的时候：while, when, as ；
eg：When I was watching TV, my mother came back.
eg：My father is cooking while my mother is reading newspaper.
eg：As time went by, the days became longer and longer.
（2）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.
（3）特殊单词：by the time that, every/each time（使用时后面不要再加when）
eg: I slept until midnight.
Wait till I call you.
She didn’t arrive until 6 o’clock.
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 (rapid eye movement) sleep—that repeats approximately every 90 minutes