英语定语从句思维导图（详细实用版）

摘要：本质：充当定语的从句，修饰主句中的先行词（名词/代词），功能是补充说明先行词的“性质、特征、所属、时间、地点、原因”等信息。- 结构公式：先行词 + 关系词（连接作用） + 从句（完整句子结构，缺主语/宾语/状语等成分，由关系词补充）例：This is th

一、定语从句核心定义

- 本质：充当定语的从句，修饰主句中的先行词（名词/代词），功能是补充说明先行词的“性质、特征、所属、时间、地点、原因”等信息。
- 结构公式：先行词 + 关系词（连接作用） + 从句（完整句子结构，缺主语/宾语/状语等成分，由关系词补充）
例：This is the book that I bought yesterday.（先行词“the book”，关系词“that”代替先行词在从句中作宾语）

二、定语从句分类（按功能）

1. 限制性定语从句

- 作用：先行词不可缺少的修饰语，去掉后主句意思不完整、不明确。
例：Students who work hard will pass the exam.（去掉从句后“Students will pass the exam”，无法明确“哪些学生”，意思不完整）
- 标点：与主句之间无逗号分隔。
- 关系词：可根据成分用that/which/who/whom/whose/when/where/why（that使用频率高）。

2. 非限制性定语从句

- 作用：对先行词进行补充说明，去掉后主句意思仍完整，仅损失额外信息。
例：My hometown, which is in the south of China, has a long history.（去掉从句后“My hometown has a long history”，意思完整，从句仅补充家乡位置）
- 标点：与主句之间必须用逗号分隔。
- 关系词限制：
- 不能用 that 引导；
- 先行词为整个主句时，只能用 which/as（as可放句首，which不可），例：As is known to all, he is a good student. / He is a good student, which makes his parents proud.

三、关系词分类与用法（核心实用考点）

（一）关系代词：在从句中作主语/宾语/定语，代替先行词（人/物）

关系代词指代对象从句中可作成分关键用法与例句
who 人（主格）主语先行词指人，从句缺主语：The teacher who taught me is kind.
whom 人（宾格）宾语先行词指人，从句缺宾语（可省略，介词后不可省）：The boy whom you met yesterday is my brother. / The girl to whom you talked is Lucy.
whose 人/物（所有格）定语（后接名词）表“先行词的”，可替换为“of which/of whom”：This is the girl whose hair is long.（= the girl of whom the hair is long）；This is the book whose cover is red.（= the book of which the cover is red）
which 物/整个主句主语/宾语 1. 指物：The pen which I lost is black.（作宾语，可省略）；2. 指整个主句（非限制性）：He failed the exam, which surprised us.
that 人/物主语/宾语 1. 通用（除非限制性从句、介词后）；2. 必须用that的场景（见下文“特殊规则”）：This is the best film that I have seen.
as 人/物/整个主句主语/宾语 1. 引导非限制性从句，常与“as is known/reported/expected”等搭配：As we all know, English is important.；2. 与such/the same搭配：This is such a beautiful place as everyone likes.

（二）关系副词：在从句中作状语（时间/地点/原因），= “介词 + which”

关系副词指代对象从句中作成分等价结构例句

when 时间（先行词：time/day/year等）时间状语 = on/in/at + which I remember the day when I joined the club.（= the day on which I joined the club）

where 地点（先行词：place/city/school等）地点状语 = in/at/on + which This is the school where I studied.（= the school in which I studied）

why 原因（仅先行词为reason）原因状语 = for + which The reason why he was late is clear.（= the reason for which he was late）

四、特殊规则（高频易错点）

1. 必须用that的5种场景

- 先行词被形容词最高级修饰（best/most beautiful等）：This is the tallest building that I have ever seen.

- 先行词被序数词修饰（first/second等）：The first thing that you should do is to study.

- 先行词被 the only/the very/the same/the last 修饰：He is the only student that passed the exam.
- 先行词为 all/everything/nothing/something/anything 等不定代词：Everything that he said is true.
- 先行词既有人又有物：I will never forget the people and places that I visited last year.

2. 关系词省略的2种情况

- 关系代词在从句中作宾语（who/whom/which/that）：The book（that/which）I read is interesting.
- 关系副词when/where/why在“the time/the place/the reason”后，可省略（或用that代替）：I don’t remember the time（when/that）we met.

3. 介词+关系词的用法

- 介词选择：根据从句中动词的固定搭配（talk to / depend on）或先行词的搭配（a house in）；
例：The man with whom she talked is my uncle.（talk with sb.）
- 关系词：指人用whom，指物用which，不可用that；
- 简化：介词可提前，也可放在从句动词后（此时关系词可省略）；
例：The pen（which/that）I wrote with is lost. = The pen with which I wrote is lost.