介词+关系词1）介词后面的关系词不能省略
2）that前不能有介词
3）某些在从句中充当时间，地点或原因状语的"介词+关系词"结构可以同关系副词when和where互换
ThisisthehouseinwhichIlivedtwoyearsago
ThisisthehousewhereIlivedtwoyearsago
Doyourememberthedayonwhichyoujoinedourclub
Doyourememberthedaywhenyoujoinedourclub
关系代词that的用法1）不用that的情况a)在引导非限定性定语从句时
(错)Thetree,thatisfourhundredyearsold,isveryfamoushere
b)介词后不能用
Wedependonthelandfromwhichwegetourfood
Wedependonthelandthat/whichwegetourfoodfrom
2)只能用that作为定语从句的关系代词的情况a)在therebe句型中，只用that，不用which
b)在不定代词，如：anything,nothing,theone,all,much,few,any,little等作先行词时，只用that，不用which
c)先行词有theonly,thevery修饰时，只用that
d)先行词为序数词、数词、形容词最高级时，只用that
e)先行词既有人，又有物时
举例：Allthatisneededisasupplyofoil
所需的只是供油问题
Finally,thethiefhandedeverythingthathehadstolentothepolice
那贼最终把偷的全部东西交给了警察
