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thatThat'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thatSheistheonlypersonthatIknowinthiscompany.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thatThefirstthingthatIwanttodoistotakeitaway.4.当先行词同时含有"人"或"物"时,关系代词应用that5.在固定结构thesame...that...;so...that...;such...that...以及itis/was...that...的强调句型中,要用thatThisisthesameparkthatweoncevisited.6.如主句以therebe开头时,关系代词应用thatThereisaroomthathastwowindows.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whichShewonthecompetition,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whichIknowthatwhichyoutoldme.4.如先行词和定语从句之间被其它较长的成分分隔,常用whichLarrytoldherthestoryoftheyoungairmanwhichInarratedatthebeginningofthisbook.(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whichAshopshouldkeepastockofthosegoodswhichsellbest.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.关系代词that与which指物时，往往可以互换，但在下列句中多用that：1.Allthatglittersisnotgold.闪光的东西不都是金子。（不定代词包括复合词something等多后接that）2.ItwasthelargestmapthatIeversaw.那是我所见过的最大的地图。（前有形容词最高级等的先行词之后多用that）3.Itwaseducationthatbroughtaboutsuchabigchangeinhislife.是教育给他的生活带来了如此大的变化。（强调结构用that）4.Whichwasthehotelthatwasrecommendedtoyou?哪一个是推荐给你的旅馆？(这里用that显然是为了避免重复which)5.Theroomthatfacesthesouthismine.朝南的那个房间是我的。（that在此表固有的特点）在下列句中多用which:6.Beijing,whichwasChina'scapitalformorethan800years,isrichinculturalandhistoricrelics.(非限制性定语从句一般皆用which)7.LarrytoldherthestoryoftheyoungairmanwhichInarratedatthebeginningofthisbook.拉里把我在书本开头叙述过的那个关于一个青年飞行员的故事讲给她听。（离先行词较远时常用which，如在此处用that,则会有指前面的airman