than,as…as…,notsoas…,(not)thesameas,the+比较级;
eg:Lighttravelsfastthansound.
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:WhenIwaswatchingTV,mymothercameback.
while:强调两个动作同时进行,一边……一边……;
eg:Myfatheriscookingwhilemymotherisreadingnewspaper.
eg:Astimewentby,thedaysbecamelongerandlonger.
(2)一……就……:assoonas,主将从现;用directly,immediately,instantly连接两个句子;一些名词如theminute,themoment,theinstant也可表示;nosooner…than,hardly…when后面的句子需要倒装;
eg:Iwillwritetoyouthemoment/minuteIarrivedinParis.
(3)特殊单词:bythetimethat,every/eachtime(使用时后面不要再加when)
(4)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:Isleptuntilmidnight.
Shedidn'tarriveuntil6o'clock.
②Until可用于句首,而till通常不用于句首,通常用于句中;
eg:Untilyoutoldme,Ihadheardnothingofwhathappened.
eg:Asyousleepyoupassthroughasequenceofsleepstates—lightsleep,deepsleepandREM(rapideyemovement)sleep—thatrepeatsapproximatelyevery90minutes.