第十七章 主词动词一致性

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      一、核心定义

      主词动词一致性(Subject-verb agreement)指句子主词与动词在单复数形式上必须匹配——主词为单数时动词用单数形式,主词为复数时动词用复数形式。中文无此类字尾变化,是英文写作高频易错点,需重点掌握特殊情况的判断逻辑。

      二、名词本身的单复数特殊情况

      1. 单数形用复数动词

      • 表“人们”的 people:There are people waiting outside.(people=“人们”,无-s 仍为复数)

      • 单复同形的名词(fish, sheep 等):Many fish live in this lake.(fish 表“鱼的数量”时单复同形,表“种类”时用 fishes)

      • 特定集体名词(police, cattle 等):The police are investigating the case.(police 无单数形,固定用复数动词)

      2. 复数形用单数动词

      • 表“学科/疾病”的-ics 结尾名词(mathematics, physics, mumps 等):Mathematics is an exact science.(-ics 表学科/疾病时为抽象名词,用单数)

      • 度量衡/时间/货币单位(dollars, hours, kilometers 等):Seven thousand dollars is a lot of money.(单位虽为复数,实则表“一笔/一段”,视为单数)

      3. 单复数动词皆可

      • 常用复数形的不可数名词(media, data, bacteria 等):The media has/have reported this event.(media=“媒体”,惯⽤复数形,动词可单可复)

      • 集合名词(family, committee, team 等):

        • 表“单位整体”用单数:The family is large.

        • 表“单位成员”用复数:The family are all doctors.

      三、限定词相关的一致性规则

      1. 表范围的限定词(all of, some of, most of 等)

      • 规则:动词单复数由限定词后的名词决定,与限定词本身无关。

      • 示例:

        • All of the students have left.(students 为复数 → 复数动词)

        • All of the money is spent.(money 为不可数 → 单数动词)

      2. less 与 fewer 的区分(高频易错点)

      • less:修饰不可数名词(表“更少”),搭配单数动词。

        • 示例:Less time is needed for this task.

      • fewer:修饰可数名词复数(表“更少”),搭配复数动词。

        • 示例:Fewer people go to cinemas now.

      • 禁忌:不可数名词用 fewer(如 fewer water)、可数名词用 less(如 less books)均为错误。

      3. a number of 与 the number of 的差异

      • a number of + 可数名词复数 → 复数动词(表“若干”):A number of accidents happened.

      • the number of + 可数名词复数 → 单数动词(表“数量”):The number of accidents is increasing.

      4. none of 的特殊用法

      • 后接不可数名词 → 单数动词:None of the food was left.

      • 后接可数名词复数 → 单复数动词皆可:None of the guests was/were late.

      四、主词含特殊结构的一致性判断

      1. 主词+介系词短语

      • 规则:介系词短语仅为修饰语,忽略不计,动词单复数由核心主词决定。

      • 示例:

        • John together with his friends is coming.(核心主词是 John→ 单数动词)

        • The list of candidates is in the newspaper.(核心主词是 list→ 单数动词)

      2. 对等连接词连接主词

      (1)and/both…and

      • 表“两个独立对象”→ 复数动词:Your brother and John are coming.

      • 表“同一人/物”→ 单数动词:The senator and delegate is here.(同一人兼具两重身份)

      • 表“整体概念”→ 单数动词:Bread and butter is my breakfast.(面包涂奶油视为一种食物)

      (2)or/either…or/neither…nor

      • 规则:遵循“就近原则”,动词单复数与靠近动词的主词一致。

      • 示例:

        • John or his sisters are going.(sisters 靠近动词 → 复数)

        • Neither he nor his friend was late.(friend 靠近动词 → 单数)

      (3)but/not only…but also

      • but=except,动词看前面的主词:Everyone but Tom was present.(核心主词是 everyone→ 单数)

      • not only…but also 遵循“就近原则”:Not only you but also I am at fault.(I 靠近动词 → 单数)

      3. 特殊句型(比较级、关系从句、分裂句)

      • 比较级(as well as, no less than):动词由主要主词决定,连接词后的部分视为修饰语:I as well as you am responsible.(主要主词是 I→ 单数)

      • 关系从句:关系词(who/which)的动词单复数看先行词:People who talk too much are annoying.(先行词 people→ 复数)

      • 分裂句(it is…that):that 从句动词单复数看被强调的先行词:It was the boys that were late.(先行词 boys→ 复数)

      4. 动名词/不定词/名词从句作主词

      • 规则:此类主词视为“单一概念”,一律用单数动词。

      • 示例:

        • Smoking is harmful.(动名词作主词)

        • To learn English well takes time.(不定词短语作主词)

        • What he said is true.(名词从句作主词)

      五、核心要点总结

      1. 核心逻辑:动词单复数由“主词的实际单复数”决定,而非表面形式(如复数形名词可能表单数概念)。

      2. 关键技巧:忽略主词后的修饰语(介系词短语、同位语等),聚焦核心主词。

      1. 高频易错点:less 与 fewer 的区分、集合名词的单复数选择、对等连接词的“就近原则”。

      2. 特殊情况:单位名词、学科/疾病类名词、动名词/名词从句作主词时的单数动词要求。