【只用that不用who的八种情况】在英语语法中，关系代词“that”和“who”都可以引导定语从句，但在某些情况下，只能使用“that”，而不能使用“who”。掌握这些规则对于正确使用英语非常关键。以下是对“只用that不用who”的八种常见情况的总结。
一、
1. 当先行词是不定代词时：如“everything, something, nothing, anything”等。
2. 当先行词是指示代词时：如“this, that, these, those”等。
3. 当先行词是表示时间或地点的名词时：如“time, place, way”等，但有时也可以用“when, where, in which”等。
4. 当关系代词在从句中作宾语时：尤其是当先行词为物时。
5. 当先行词被最高级修饰时：如“the best, the first, the last”等。
6. 当先行词被序数词修饰时：如“the first, the second”等。
7. 当先行词指人又指物时：此时只能用“that”。
8. 当句子中有“all, every, any, no”等限定词时：通常使用“that”。
以上情况是英语学习者在使用关系代词时需要注意的关键点，正确使用“that”可以避免语法错误，提高语言表达的准确性。
二、表格总结
| 情况 | 先行词示例 | 使用“that”原因 | 示例句子 |
| 1. 不定代词 | everything, something | “who”不能修饰不定代词 | Everything that he said was true. |
| 2. 指示代词 | this, that, those | “who”不能修饰指示代词 | That is the book that I need. |
| 3. 时间/地点名词 | time, place, way | “that”可代替“when, where, in which” | This is the place that we visited. |
| 4. 宾语位置 | 物（如book, car） | “who”仅指人，不用于物 | The man (that) you saw is my brother. |
| 5. 最高级修饰 | the best, the first | “who”不用于最高级 | She is the girl that won the prize. |
| 6. 序数词修饰 | the first, the second | “who”不用于序数词 | This is the first time that I have been here. |
| 7. 人与物混合 | people and things | “who”仅指人，不能涵盖物 | The people and things that were there were unforgettable. |
| 8. 限定词修饰 | all, every, any | “who”不用于限定词后 | All that glitters is not gold. |
通过以上总结，我们可以更清晰地理解在哪些情况下应该使用“that”而不是“who”。掌握这些规则有助于提升英语写作和口语的准确性，避免常见的语法错误。
