1.that即可代表事物也可代表人,which代表事物;它们在从句中作主语或宾语,that在从句中作宾语时常可省略关系词,which在从句中作宾语则不能省略.而且,如果which在从句中作“不及物动词+介词”的介词的宾语,注意介词不要丢掉,而且介词总是放在关系代词which的前边,但有的则放在它原来的位置
2.which作宾语时,根据先行词与定语从句之间的语义关系,先行词与which之间的介词不能丢
3.代表物时多用which,但在带有下列词的句子中用that而不用which,这些词包括all,anything,much等,这时的that常被省略
当先行词是anything,everything,nothing(something除外),few,all,none,little,some等代词时,或者是由every,any,all,some,no,little,few,much等修饰时
(1)HaveyoutakendowneverythingthatMr.Lihassaid?
(2)Thereseemstobenothingthatseemsimpossibleforhimintheworld.
(3)Allthatcanbedonehasbeendone.
(4)ThereislittlethatIcandoforyou.
Thisistheverynovel(that)Iwanttobuy.此句的先行词是物.
MrSmithistheonlyforeigner(that)heknows.此句的先行词是人.