1.只能使用that,不用which 的情況：
(1) 先行詞是all,few,little,nothing,everything,anything 等不定代詞時(shí).例如：
All that he said is true.
(2) 先行詞被only,no,any,all,等詞修飾時(shí).例如：
He is the only foreigner that has been to that place.
(3) 先行詞是序數(shù)詞或被序數(shù)詞修飾的詞.例如：
He was the second (person) that told me the secret.
(4) 先行詞是形容詞最高級(jí)或被形容詞最高級(jí)修飾的詞.
This is the best book (that) I have read this year.
(5) 先行詞既包括人又包括物時(shí).例如：
He talked about the people and the things he remembered.
2.只能用which,不用that 的情況：
(1) 在非限制性定語從中.例如：
The meeting was put off,which was exactly what we wanted.
(2) 定語從句由介詞+關(guān)系代詞引導(dǎo),先行詞是物時(shí).例如：
The thing about which he is talking is of great importance.