定语从句宜用that而不用which的情况及宜用which不宜用that的情况 1、 定语从句中宜用that而不用which的情况 1) 先行词为all much little everything anything nothing none few the one 等不定代词； . I mean the one that was bought yesterday. 2) 先行词被形容词最高级或被only any few little no all one of等修饰时； . It’s the most important task that should be finished soon. 3) 先行词为数词或被序数词（包括last）所修饰时； . Look at these flowers. You can see the two that you gave me. 4) 先行词中既有人又有物时； . We were deeply impressed by the teachers and schools that we had visited. 5) 主语中已有who和which的； 6) 先行词在主句中做表语或关系代词在从句中做表语时； . It’s book that will help you a lot. My hometown is no long the place that it used to be. 2、 宜用which不宜用that的情况 1) 关系代词前有介词时； . This is the room in which Lu Xun lived. 2) 非限定性定语从句中； . He has a daughter, who works in a hospital. 3) 先行词本身是that时； . The clock is that which tells the time
