(1) 非限定性定語從句：先行詞（即名詞）後有一個逗號；
eg: In our school，there were 8 foreign teachers who come from Australia.（限定性定語從句）
In our school，there were 8 foreign teachers， who come from Australia.（非限定性定語從句）
限定性定語從句：定語從句和關係詞關係非常緊密，刪掉定語從句後，整個句子意思會改變；
非限定性定語從句：定語從句和關係詞關係不是很緊密，刪掉定語從句後，整個句子意思不會改變，定語從句只起到補充說明的意義；
eg：This is the house which we bought last month.
（2）非限定性定語從句：
①先行詞是前面的整句話；
eg: He won the first place in the competition, which is out of our expectation.
We will spend the Spring Festival in Guangzhou, which was decided last year.
This is the house, which we bought last month.
② 非限定性定語從句：which引導非限制性定語從句只能放在後面，as則只能放在句子前面；
eg: Smoking is harmful to our heath, which we know.
Smoking is harmful to our heath, as we know.
As we know, smoking is harmful to our heath.
eg：Alice received an invitation from her boss（ ） came as a surprise .
A. It B. that C. as D. which
(3)that和which的區別：
①什麼時候不能用that，只能用which：非限定性定語從句中，即逗號之後；
eg：The tree, that is 400 years old, which is very famous here.
②什麼時候不能用that，只能用which：非限定性定語從句中，即逗號之後；介詞後面不能用that，只能用which；
eg：The tree, that is 400 years old, which is very famous here.
We depend on the land, from which we can get our food.
in that：因為；
（4）什麼時候不能用which，只能用that：
① 前面的先行詞是不定代詞，包括all，anything，nothing，the one， much，little等；
eg：Have you taken down everything that Mr. Lee has said?
② 如果先行詞中出現了the only, the very等；
eg：This is the only way that we can think out.
③ 如果先行詞中出現了序數詞和形容詞最高級；
eg：This is the best film that I have ever seen.
④ 如果先行詞中即有人，又有物；
eg：They are talking about the school and the teachers that they visited yesterday.
例：Medical researchers are painfully aware that there are many problems
(他們至今還沒找到答案）.
They haven’t found solutions/answers to these problems.
There are many problems which they haven’t found solutions/answers to.
例：（與我成長的地方相比），this town is more prosperous and exciting.
Compared with the place in which/where I grew up,
例：（聽到他告訴我的消息），I could’t help laughing．
Hearing the news which/that he told me,
例：Career experts say that one of the ways job seekers can stay safe while using the Internet to search out jobs is to conceal their identities.
當先行詞中是the way的時候，後面的連接詞可以用that，可以用which和in which，甚至可以不填；
編輯推薦：◇ 2013年12月英語六級基礎語法解析匯總
（實習編輯：張心悅）