英语知识点总结（2026-03-10）
1. I just learned ... 的时态
I just learned that ... 可以表示“我刚知道……”。
现代英语里，just + 一般过去时 很常见，尤其是美式英语。
也可以说：I've just learned that ...，更强调“刚刚完成这个动作”。
示例：
I just learned that there is an app called xxx.
I've just learned that there is an app called xxx.
补充：宾语从句中的时态是否必须后退？
“主句是过去时，从句就一定后退一个时态”并不是绝对规则。
如果从句内容仍然是真实、当前有效的事实，常常不后退。
示例：
I just learned that there is an app called xxx. ✅
I just learned that there was an app called xxx.（强调过去存在、现在未必存在）
2. 宾语从句里 which、whose 的作用
which、whose 既起连接作用，也在从句内部充当成分。
which
常可作：
主语
宾语
定语
示例：
I don't know which book is yours.
She asked which was better.
He couldn't decide which he should choose.
whose
常作：
定语
示例：
I wonder whose bag this is.
She asked whose idea won the competition.
3. 引导词和先行词不是一回事
先行词：只出现在定语从句中，是被修饰的那个词。
引导词：连接主句与从句，并且有时在从句中充当成分。
示例：
The book that I bought is interesting.
book = 先行词
that = 引导词
所以：引导词 ≠ 先行词。
4. 宾语从句要点
宾语从句在句中作宾语，常放在动词、介词、形容词之后。
常见引导词
that：通常不作成分，有时可省略
whether / if
what / who / which / whose / when / where / why / how
that 的省略
通常可省：
I think (that) he is right.
通常不省：
从句较长时
有多个并列的 that 从句时，后面的 that 常不能省
5. 不定式为什么叫“不定式”
不定式（infinitive）之所以叫“不定”，是因为它不像谓语动词那样受人称、数、时态的限定。
例如：
to go
to study
它本身不表示：
第几人称
单复数
一般现在 / 一般过去 这类限定变化
因此叫“不定式”。
6. 动名词 vs 现在分词
二者形式相同，都是 V-ing，但功能不同。
动名词（gerund）
更接近名词，常作：
主语
宾语
表语
示例：
Reading is important.
I enjoy reading.
现在分词（present participle）
更接近形容词 / 副词功能，常作：
定语
状语
表语的一部分
构成进行时
示例：
The sleeping baby is cute.
She came in, smiling.
They are reading.
判断关键：看它在句子里做什么成分，而不是只看形式。
7. if I were you 为什么用 were
这是虚拟语气，表示与现实不符的假设。
If I were you, I would apologize.
这里不用 was，是因为说话人并不是“你”，属于假设语气。正式英语中常用 were。
8. not only ... but also ... 的平行结构
两部分最好保持语法一致。
不够平行：
reduce people's attention spans
be harmful to their mental health
更平行：
reduce people's attention spans
harm their mental health
推荐句：
Many studies show that excessive reliance on social media may not only reduce people's attention spans but also harm their mental health in the long term.
9. research vs studies
research 通常是不可数名词：much research
表示一项项具体研究时，常用：many studies
示例：
Much research shows that ...
Many studies show that ...
10. attention vs attention span
attention：注意力（较抽象）
attention span：注意力持续时间（更具体、更自然）
所以：
reduce people's attention spans
比decrease people's attention
更自然。
11. in the long run vs in the long term
in the long run：偏口语
in the long term：偏书面 / 学术写作
IELTS / 议论文中通常 in the long term 更稳妥。
12. 可直接套用的高级表达
excessive reliance on
overreliance on
impair attention
undermine mental well-being
a growing body of research indicates that ...
示例：
A growing body of research indicates that overreliance on social media may impair attention and negatively affect mental health over time.
13. 今天的翻译练习总结：社交媒体句子
题目
许多研究表明，过度依赖社交媒体不仅可能降低人们的专注力，还可能对心理健康产生长期的负面影响。
原句
Many researches shows that relying on social media extremely may not only decrease people's attention, but also be harmful to mental health in the long run.
主要错误总结
1）research 一般不用复数
research 通常是不可数名词，所以不用 many researches
更自然的说法：much research
如果想表达“一项项具体研究”，用：many studies
2）主谓一致
many studies 后面用 show
不能说：Many studies shows
3）副词位置和搭配不自然
relying on social media extremely 不地道
更自然：
rely too heavily on social media
rely excessively on social media
show excessive reliance on social media
4）attention 不如 attention spans 自然
decrease people's attention 可以理解，但不够地道
更自然：
reduce people's attention spans
shorten attention spans
weaken concentration
5）be harmful to mental health 可以，但还可以更简洁有力
原表达没有语法错误
但为了和前面的 reduce 保持平行，通常更推荐：
harm their mental health
damage mental well-being
negatively affect mental health
6）not only ... but also ... 要注意平行结构
更好的并列方式：
reduce people's attention spans
harm their mental health
而不是：
reduce people's attention spans
be harmful to their mental health
你这次练习的修改过程
初步改正后
Many studies show that relying excessively on social media may not only reduce people's attention spans, but also be harmful to their mental health in the long run.
这一版已经基本正确。
更好的平行版本
Many studies show that relying excessively on social media may not only reduce people's attention spans but also harm their mental health in the long run.
更适合写作的版本
Many studies show that excessive reliance on social media may not only reduce people's attention spans but also harm their mental health in the long term.
今天提到的同义替换
表示“很多研究表明”
many studies show that ...
much research shows that ...
a lot of research shows that ...
a growing body of research indicates that ...
a substantial body of research suggests that ...
表示“过度依赖社交媒体”
rely excessively on social media
rely too heavily on social media
excessive reliance on social media
excessive dependence on social media
overreliance on social media
表示“降低注意力 / 注意力持续时间”
reduce people's attention spans
shorten attention spans
impair attention
weaken concentration
diminish attention spans
表示“危害心理健康”
harm their mental health
negatively affect mental health
damage mental well-being
undermine mental well-being
have detrimental long-term effects on mental health
表示“长期来看”
in the long run
in the long term
over time
今天提到的习惯用法 / 更地道表达
attention span 比 attention 更适合这个语境
in the long term 比 in the long run 更适合 IELTS / 学术写作
excessive reliance on 比 relying excessively on 更书面、更凝练
harm their mental health 比 be harmful to their mental health 更利落，也更适合和前面的动词构成平行结构
今天提到的高级词汇 / 表达
excessive reliance on
overreliance on
excessive dependence on
impair attention
diminish attention spans
undermine mental well-being
detrimental long-term effects
a growing body of research indicates that ...
a substantial body of research suggests that ...
可直接背诵的升级版句子
标准稳妥版
Many studies show that excessive reliance on social media may not only reduce people's attention spans but also harm their mental health in the long term.
更高级版
A growing body of research indicates that overreliance on social media may impair attention and negatively affect mental health over time.
更正式版
A substantial body of research suggests that excessive dependence on social media may not only diminish attention spans but also have detrimental long-term effects on mental health.