第一,為了使句意完整如
I have many friends,some of whom are businessmen.
Mr Black has two sons ,both of whom like sports.
第二,定語從句中謂語是由動(dòng)詞加介詞構(gòu)成的短語,可把介詞提到關(guān)系代詞之前如
The man with whom my father is talking is our teacher.
定語從句最主要的是要分清關(guān)系代詞和關(guān)系副詞的區(qū)別.代詞有which that who whom whose as它們?cè)趶木渲凶髦髡Z,賓語,表語或定語,所以當(dāng)從句中缺少其中某一種以上成份時(shí)就選擇關(guān)系代詞.
This is the city that/which we visited last year.(這句中缺少visit的賓語)
Anyone who breaks the law must be punished.(這句中缺少主語且表人)
The book that/which I bought yesterday is very interesting.(這句中缺少主語且指物)
The boy whose father is a lawyer is our monitor.(這句中缺少定語修飾father)
I live in the house whose door faces the south.(同上)
Kate is no longer the girl that she used to be.(作表語)
如果先行詞在句中作狀語用關(guān)系副詞引導(dǎo),有where when why
This is the city where Tom was born.=Tom was born in the city所以說先行詞在從句中作關(guān)語.
I will never forget the days when we worked together.先行詞在從句作時(shí)間狀語.
The reason why he was late is that he was ill .