that常用作關係代詞，可指代某人，也可指代某物，指物時有的時候可用which替換that，指人時可用who替換。但在下列情況下，一般用that。
一、that指代某物事時
1.先行詞爲all, few, little, much, the one, something, anything, everything, nothing等時。如：
（1）We'll do all that we can to protect the endangered plants and animals.
我們將盡我們的最大努力來保護那些瀕危的動植物。
(2) There is much that I wan to tell you.
我有很多想要告訴你的話。
(3) Is there anything that I can do for you?
有什麼我可以幫你的嗎？
2.先行詞被all, every, no, some, any, (a)few, (a)little, much等限定詞修飾時。如：
(4) You can borrow any book that you want to read in our school library.
在我們圖書館，你可以借任何你想讀的書。
3.先行詞被序數詞或形容詞最高級修飾時。如：
（5）This is the most beautiful city that I've ever seen.
這是我見過的最漂亮的城市。
4.先行詞被the only, the very, the right, the last等修飾時。如：
（6）This is the very factory that they visited last summer holiday.
這恰好是他們去年參觀的那個工廠。
（7）This is the only painting in this style that we have.
這種風格的畫我們僅有一幅。
5.先行詞是並列結構，既有人又有物時。如：
（8）He talked happily of the writer and his books that interested him.
6.先行詞前有the same修飾，表示和先行詞是同一物時。如：
（9）This is the same purse that I lost yesterday.
這就是我昨天丟的那個錢夾。
注：如果表示的是與先行詞同一類或相似的某物，則用the same…as….如：
（10）This is the same purse as I lost yesterday.
這個錢夾和我昨天丟的那個一樣。
7.先行詞爲數詞時。
（11）Look at the books on the bookshelf. You can see the two that you bought me for my birthday.
瞧書架上那些書。你可以看到我過生日時你買的那兩本。
8.如果which引導的定語從句中又含有一個定語從句，爲避免重複，第二個定語從句用that。如：
（12）They built a factory which produced things that had never been seen.
他們建了一工廠，生產以前從未見過的.東西。
9.以which作主語開頭的特殊問句，爲了避免重複，定語從句用that。如。
（13）Which is the bus that you will take?
你要乘的是哪一班車？
10.關係代詞在定語從句中作表語時，而且通常省略。如：
（14）My hometown is no longer the place that it used to be.
我的家鄉再也不是以前那個樣子了。
11.關係代詞在there be句型中作主語時,而且常可以省略。如：
（15）This is the fastest train (that) there has ever been.
這是有史以來最快的列車。
二、that指代某人時。
1.泛指某人時。如：
（16）He is a man that is never at a loss.
他是一個從未一籌莫展的人。
2.主句是以作主語的who開頭的特殊問句，爲了避免重複時。如：
（17）Who is the person that is talking with our headmaster?
和我們校長說話的那人是誰？
3.先行詞前有the same時。如：
（18）This is the same man that gave us a talk last year.
這和去年給我們作報告的是同一人。
4.關係代詞在定語從句中作表語時。如：
（19）He has changed. He was not the man (that) he was 10 years ago.
他變了。他再也不是10年前的他了。
另外，that也可用作關係副詞，表示時間、地點、原因和方式，在口語中可以用來代替when, where, why引導的定語從句。在以下名詞day, year, time, moment, reason, place等作先行詞時，可用that作關係副詞引導定語從句。如：
（20）I'll never forget the day (that) I joined the League.
我永遠不會忘記我入團的那一天。
（21）Is this the reason (that) they were late for the meeting?
這就是他們開會遲到的原因嗎？
（22）We want to find a place (that) we can have a picnic.
我們想找一個我們能野餐的地方。
（23）This is the first time that I have been abroad for traveling.
這是我第一次到國外去旅遊。
（注：先行詞是time,前面有序數詞或last修飾時，常用that引導定語從句或者省略。）
當先行詞爲表示方式的詞the way時，可用that引導定語從句, that常可以省略。
（24）I don't the way you speak to her.
我不喜歡你和她說話那種方式。
鞏固練習：
1. This is the same book______ I lost the other day. There's my name on it.
A. that B. as C. / D. which
2. I hope that the little _______ I have been able to do does good to them all.
A. which B. what C. that D. when
3. The first place ______ the children were taken to see was their workshop.
A. that B. which C. what D. where
4. Tell me everything _________ you know.
A. which B. about that C. about which D. that
5. This is the biggest library ______ I have ever seen.
A. which B. what C. where D. that
6. This is the very person _______I am looking for.
A. which B. that C. who D. whom
7. What surprised me was not what he said but _________ he said it.
A．the way B．in the way that
C．in the way D．the way which
8. This is all ________ I can do for you.
A. which B. what C. it D. /
9. The book doesn't say much _______ amuses children.
A. what B. that C. whose D. to which
10. There is nothing about him ________ I know of.
A. that B. which C. whom D. who
參考答案：
1～5 ACADD 6～10 BADBA
