关于that和which在引导定语从句时的用法与区别

一、核心区别

1. 限定性 vs 非限定性定语从句

   • that：仅用于限定性定语从句（无逗号，对先行词起关键限定作用）

     例句：This is the book that I borrowed from the library.
     （“我借的书”是特定指代，不可省略从句）

   • which：可用于非限定性定语从句（有逗号，补充说明先行词，可删去不影响主句）

     例句：My laptop, which I bought last year, suddenly crashed.
     （补充说明“笔记本电脑”，主句仍完整）

2. 先行词类型

   • that：可指人或物（如：the man that you met）；which仅指物。

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二、必须用that的8种情况

1. 先行词为不定代词（all, any, everything, nothing等）:

   例句：All that glitters is not gold.

2. 先行词被特定词修饰（the only, the very, the same等）:

   例句：This is the only seat that is available.

3. 先行词含最高级或序数词（the best, the first等）:

   例句：It’s the most interesting movie that I’ve ever seen.

4. 先行词既有人又有物:

   例句：They discussed the people and things that impressed them.

5. 主句以疑问词开头（who, which等）:

   例句：Who that knows him would trust him?

6. 关系代词作从句表语:

   例句：China is not the country that it was.

7. 先行词是time表次数（可省略）:

   例句：I remember the first time (that) we met.

8. 主句为There be结构:

   例句：There is nothing that can stop us.

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三、必须用which的3种情况

1. 非限定性定语从句（有逗号）:

   例句：The Eiffel Tower, which was built in 1889, is iconic.

2. 介词后引导从句（介词+which）:

   例句：This is the house in which I grew up.

3. 先行词为those+复数事物:

   例句：Learn those skills which will be useful.

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四、特殊情况与易错点

• 可互换的情况：若先行词是物且未被上述规则限制，两者可互换：

  例句：The car that/which I bought is red.

• the same…as vs the same…that：
  • the same…as 强调“同类”，the same…that 强调“同一物” 。
• 固定搭配：如“the way (that/in which)…”或“the reason (that/why)…” 。

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五、总结表格