定语从句

定语从句是一个小从句，紧跟在名词后面，说明你指的是哪个人或哪个东西，或者补充有关它的信息。它以关系代词（who、which、that）开头。关系代词代替了 he / she / it / they……，所以不用再重复那个主语或宾语。

• I have a neighbour. She grows vegetables on her roof. → I have a neighbour who grows vegetables on her roof.

  我有个邻居。她在屋顶上种菜。→ 我有个在屋顶上种菜的邻居。（who 代替 she）

• We bought a fan. It's really quiet. → We bought a fan which is really quiet.

  我们买了一台风扇。它真的很安静。→ 我们买了一台非常安静的风扇。（which 代替 it）

• The man who fixed my bike didn't charge me anything.

  帮我修自行车的那个人一分钱都没收我。

选择关系代词时问自己两个问题：前面的名词是人还是物？关系代词在从句里做主语还是宾语？Ø 表示关系代词可以省略。

• I want a phone which takes good photos at night.

  我想要一部晚上也能拍出好照片的手机。

• Do you know anyone that speaks Korean?

  你认识会说韩语的人吗？

• The dog that lives next door barks at everyone.

  隔壁那只狗见谁都叫。

That 既可以指人也可以指物，在口语中非常常见。指人时，书面语更常用 who。从句没有逗号时，很多美式英语作者更喜欢用 that 而不是 which；英式英语两种都用。

💡关系代词在从句中做主语时，不能省略：People who live near the river worry about floods（不说：People live near the river worry…）。没有 who，句子里就有两个谓语动词，结构就乱了。

如果关系代词是宾语——也就是它后面紧跟着另一个主语（I、you、my mum……）——就可以省略。母语者在口语中经常这样做。

• The cake (that) my mum made was delicious.

  我妈妈做的蛋糕很好吃。（that 是 made 的宾语 → 可以省略）

• Is this the charger you were looking for?

  这是你在找的充电器吗？

• The people I work with are really friendly.

  和我一起工作的人都很友好。

• The woman who called you left a message.

  给你打电话的那位女士留了言。（who 是 called 的主语 → 不能省略）

注意介词的位置：日常英语中介词放在从句末尾（the people I work with、the flat we live in）。正式书面语中可以把介词提到前面，但这时必须用 whom 或 which，不能用 that：the people with whom I work、the flat in which we live。

定语从句分两种。限制性从句告诉你是哪个人、哪个东西——去掉它，句子意思就不清楚。非限制性从句只是对听者已经知道是谁/是什么的人或物补充信息——去掉它，句子照样说得通。它放在两个逗号之间（口语中用短暂停顿表示）。

• My cousin who lives in Canada is an engineer.

  我住在加拿大的那个表哥是工程师。（暗示我有好几个表哥——说的是在加拿大的那个）

• My cousin, who lives in Canada, is an engineer.

  我表哥是工程师，他住在加拿大。（他住在哪里只是补充信息）

• Da Nang, which has a long sandy beach, is popular with families.

  岘港有一片长长的沙滩，很受家庭游客欢迎。

• We visited my grandmother, who turns 90 this year.

  我们去看望了我奶奶，她今年满 90 岁。

💡在专有名词（Da Nang、Mr Nam）或独一无二的名词（my mother、the sun）后面，定语从句几乎都是非限制性的：要加逗号，而且不能用 that。

, which 还可以指代前面的整件事，而不只是一个名词。这种用法前面总有逗号，而且只能用 which（不能用 what 或 that）。

• Lan passed her driving test first time, which surprised everyone.

  阿兰第一次就通过了驾照考试，这让所有人都很惊讶。

• The bus was late again, which meant I missed the meeting.

  公交车又晚点了，结果我错过了会议。

• 从句里的动词与前面的名词保持一致：a friend who lives…、two friends who live…、everyone who was there…（everyone 是单数）。
• 在 everything / anything / nothing / all / the only / 最高级 后面，一般用 that 或者什么都不用：Is there anything (that) I can do? —— the best film (that) I've ever seen。
• What 的意思是“……的东西”，不能跟在名词后面：What I need is a holiday。但要说：everything that he said（不说：everything what）。
• Those who = the people who（比较正式）：Those who exercise regularly sleep better（不说：They who…）。
• whose、where、when、why 和 whom 的用法见“whose / where / when 引导的定语从句”一课。

• ✗The girl who she sits next to me is from Hue.

  ✓The girl who sits next to me is from Hue.

  Who 已经代替了 she——不要再重复。

• ✗The bus goes to the airport leaves every 20 minutes.

  ✓The bus that goes to the airport leaves every 20 minutes.

  做主语的关系代词不能省略。

• ✗The film which I watched it last night was great.

  ✓The film (which) I watched last night was great.

  Which 已经是宾语了——去掉 it。

• ✗My father, that is a doctor, works in Hanoi.

  ✓My father, who is a doctor, works in Hanoi.

  逗号之间的从句不能用 that。

• ✗She didn't call me back, what was strange.

  ✓She didn't call me back, which was strange.

  指代整件事要用 which。

• ✗Everything what he said was true.

  ✓Everything (that) he said was true.

  Everything 后面用 that 或者什么都不用。