关系词as用法:•主要用于非限定性定语从句和thesame…as,such…as,as…as的结构中。非限定性定语从句中关系代词as用法:其先行词可是前面整个句子或部分内容。Eg:1)Hewaslate,asisoftenthecase.2)grammarisnotasetofdeadrules,ashasbeensaidbefore.3)他是个外国人,从他口音中我知道。Hewasaforeigner,asIknewfromhisaccent.Which和as都可以引导非限制性定语从句,用于指代前面整个句子或部分内容。Which:引导非限制性定语从句只能放主句的后面;As:引导非限制性定语从句时放主句前后均可。(as后面的谓语动词多是see,know,expect,say,mention,report等)Which和as的区别:Hedidn’ttakepartintheparty,whichmadeusunhappy.Asweknow,Chinahassucceededinhostingthe28thOlympicGames.在限定性定语从句中可以做主语、宾语或表语,既可以指人也可以指物,常用于下列结构中:1)thesameas+n.+as…“像…一样的…”Eg:It’sthesamestoryasIheardfromheryesterday.限定性定语从句中用作关系代词用法:2).such+a(n)+(adj.)+单n.(adj.)+复n./不可数n.+as…“像…一样”Eg:a)Suchgirlsasheknewwerenurses.b)Hereissuchaheavyboxasnomancanlift.3).so/as+adj.+a(n)+单n.+as…Eg:a)Hewillmarryasprettyagirlashecanfind.b)Hereissodifficultaproblemasnoneofuscansolve.这和我丢失的那只表一样。ThisisthesamewatchasIlost.这就是我丢失的那一只表。ThisisthesamewatchthatIlost.Thesame…as:修饰的东西与原物同样;Thesamethat:修饰的东西就是先行词那个东西。Goodbye!