that和which做比较,主要在于它们在定语从句中的用法 　　that和which在定语从句中都是做关系代词,指代先行词是事物的名词或代词（that还可以指代人,which不可以）.通常情况下二者可以互换. 　　区别： 　　关系代词用that（不用which）的情况： 　　1.先行词是all,anything,everything,nothing等,关系代词应用that 　　That'sallthathetoldme. 　　2.先行词前有theonly,thesame,thevery或no,little,much,any,every,all等修饰时,关系代词应用that 　　SheistheonlypersonthatIknowinthiscompany. 　　3.先行词前有序数词或形容词最高级修饰时,关系代词常用that 　　ThefirstthingthatIwanttodoistotakeitaway. 　　4.当先行词同时含有"人"或"物"时,关系代词应用that 　　5.在固定结构thesame...that...;so...that...;such...that...以及itis/was...that...的强调句型中,要用that 　　Thisisthesameparkthatweoncevisited. 　　6.如主句以therebe开头时,关系代词应用that 　　Thereisaroomthathastwowindows. 　　关系代词用which（不用that）的情况： 　　1.非限制性定语从句中关系代词一般要用which 　　Shewonthecompetition,whichmadethewholefamilyveryhappy. 　　2.关系代词前如有介词,关系代词须用which;如把介词移至句末,可用that(或省略) 　　There’sonlyoneproblemaboutwhichtheydisagree. 　　Thisisthekey(that)shewaslookingfor. 　　3.如果先行词是that,关系代词应用which 　　Iknowthatwhichyoutoldme. 　　4.如先行词和定语从句之间被其它较长的成分分隔,常用which 　　LarrytoldherthestoryoftheyoungairmanwhichInarratedatthebeginningofthisbook.(先行词为story) 　　5.在"those+复数形式的名词"结构中,其后的关系代词多用which 　　Ashopshouldkeepastockofthosegoodswhichsellbest. 　　6.一个句子中如有两个定语从句,第一个定语从句用了关系代词that,第二个从句中的关系代词宜用which;但在平行结构中,应重复同一个关系代词 　　Thisisthebookthatyouboughtwhichyouhavelost. 　　Ihaveahousewhichislocatedonthehillside,whichfacesthesouth. 　　此外,that还可引导同位语从句,which不能 　　Ihaveheardthenewsthattheyhadwonthegame.