3．指物时用that而不用which的情况
(1)当先行词为all，everything，nothing，anything，something，none，few，little，much等不定代词时。
All (that)the graduate lacks is practice.
那位毕业生缺少的只是实践。
(2)当先行词被very，both，the only，all等修饰时。
This is the only coat that I have.
这是我拥有的唯一的外套。
(3)当先行词被形容词的最高级修饰或序数词修饰时。
This is the most attractive match that I have watched.
这是我所看过的比赛中最吸引人的一场。
(4)当并列的两个先行词(分别表示人和物时)被同一个从句修饰时，关系代词用that。
She took photos of people and things (that)she was interested in.
她给她所感兴趣的人和物拍照。
(5)主句是以who，which，what开头的特殊疑问句时，定语从句一般用that引导，不用who或which。
Who was the person that helped the girl out?
帮助那个女孩摆脱困境的是谁？
(6)当关系代词在从句中作表语时，常用that。
Your disease is not the case that it used to be.
你的病已经不是过去的情况了。
