定語從句中的關係代詞有that, which, who, whom, whose等。其中，who whom 可指人，which可指物，whose，that可代替人或物。我們都知道關係代詞在句中主要是代替先行詞是人或物的名詞或代詞，表達該先行詞的意思，有着主語，賓語，定語的作用。
1.在從句中作主語
young man who came in just now is a lecturer.剛纔進來的年輕男士是個學者。
B. Here comes the good news. The team who won the basketball game is from Class two.好消息傳來了。贏得籃球比賽的這支隊來自二班。
tors that come from different places are deeply attracted by the scenery there.來自不同地方的參觀者深深地被這兒的景象所吸引。
2.在從句中作定語
unately，I eventually live in a house whose(of which) rent is lower.幸運的是，我最終住在了一個費用較低的房子裏。
B. The old man whose son is an excellent artist is kind.這個熱心老人的兒子是個傑出的藝術家。
3.在從句中作賓語，其中關係代詞前有介詞時,指人用whom
is the star with whom you have talked is the one I admire.你所談論的.她就是這個我所崇拜的明星。（不可用that）
is the watch which he found at the shop yesterday.這是他昨天在商店找到的表。
you tell me where is the man that I saw from the picture?你能告訴我從圖片上看到的這個人在哪嗎？
4.在從句中作表語,此時主要是that作爲關係代詞修飾先行詞
is a best age that we wish it to be.這是我們希望的最好的時代。（that在be 作表語）
