Appearance
Unit 116 — as (as I walked ... / as I was ... etc.)
A. as = at the same time as
as = at the same time as
也就是：
as = 当……的时候 / 与此同时 / 随着……
当两个事情同时发生时，我们可以使用 as。
1. 两件事情同时发生
You can use as when two things happen together at the same time:
We all waved goodbye to Liz as she drove away. (= we waved and she drove away at the same time)
Liz 开车离开的时候，我们都向她挥手告别。
也就是说：
we waved + she drove away
这两个动作是同时发生的。
As I walked along the street, I looked in the shop windows.
当我沿着街道走的时候，我看着商店的橱窗。
两个动作：
I walked along the street. I looked in the shop windows.
它们同时发生。
Can you turn off the light as you go out, please?
你出去的时候，可以把灯关掉吗？
这里：
as you go out = 当你出去的时候
2. as + 过去进行时
也可以表达：
在某件事情正在进行的过程中，另一件事情发生了。
结构：
something happened + as + subject + was/were doing
例如：
Kate slipped as she was getting off the bus.
Kate 正在下公交车的时候滑倒了。
这里：
she was getting off the bus ↓ 这是一个正在进行的动作
在这个过程中：
Kate slipped.
发生了“滑倒”这个动作。
We met Paul as we were leaving the hotel.
当我们正要离开酒店的时候，我们遇到了 Paul。
这里：
we were leaving the hotel
是背景动作。
we met Paul
是在这个过程中发生的事情。
结构总结
as + was/were + -ing
常表示：
正当……的时候
例如：
The phone rang as I was taking a shower.
我正在洗澡的时候，电话响了。
3. just as
You can also use:
just as = exactly at that moment
也就是：
恰好在……的时候 / 正当……的时候
它比普通的 as 更强调：
两个事情发生的时间点刚好重合。
例句
Just as I sat down, the doorbell rang.
就在我刚坐下的时候，门铃响了。
时间关系：
I sat down ↓ exactly at that moment ↓ the doorbell rang
I had to leave just as the conversation was getting interesting.
就在谈话开始变得有趣的时候，我不得不离开了。
这里有一种：
“偏偏就在这个时候”
的感觉。
4. as 表示两个事情同时逐渐变化
We also use as when two things happen together over a longer period of time.
也就是说：
两件事情不是瞬间发生，而是在一段时间内一起发展 / 一起变化。
例句
As the day went on, the weather got worse.
随着时间一天天 / 一点点过去，天气变得越来越糟。
这里有两个变化：
the day went on ↓ the weather got worse
随着时间推进，天气也不断变化。
I began to enjoy the job more as I got used to it.
随着我逐渐习惯这份工作，我开始越来越喜欢它。
两个变化同时进行：
I got more used to the job ↓ I enjoyed it more
所以这里的 as 很自然地翻译成：
随着……
5. as 和 when 的区别
Compare as and when.
这是这一单元非常重要的区别。
as：两个动作同时发生
We use as only if two things happen at the same time.
例如：
As I drove home, I listened to music. (= at the same time)
我开车回家的时候，一边听音乐。
两个动作同时发生：
drive home + listen to music
所以：
as = 同时
when：一个事情发生之后，再发生另一个事情
Use when if one thing happens after another.
例如：
When I got home, I had something to eat.
我到家后，吃了点东西。
这里不是：
到家的同时吃东西
而是：
got home ↓ had something to eat
先到家，然后吃东西。
所以这里应该使用：
when
而不是：
❌ As I got home, I had something to eat.
6. as vs when 的时间逻辑
as
A ←→ B
两个动作同时发生：
As I drove home, I listened to music.
开车回家：
─────────────→
听音乐：
─────────────→
两个动作在同一时间进行。
when
A → B
一个动作完成后，另一个动作发生：
When I got home, I had something to eat.
时间线：
got home ↓ had something to eat
7. B. as = because
As 还有另外一个非常重要的意思：
as = because
也就是：
因为 / 由于
8. as 表示原因
例句
As I was hungry, I decided to find somewhere to eat. (= because I was hungry)
因为我饿了，所以我决定找个地方吃东西。
这里的 as 不表示“当……的时候”。
它表示：
because
逻辑是：
I was hungry ↓ so I decided to find somewhere to eat
As it’s late and we’re tired, let’s get a taxi home. (= because it’s late ...)
因为已经很晚了，而且我们也累了，我们坐出租车回家吧。
We watched TV all evening as we didn’t have anything better to do.
我们整个晚上都在看电视，因为我们没有什么更好的事情可做。
这里：
as = because
As I don’t watch TV any more, I gave my television to a friend of mine.
因为我已经不看电视了，所以我把电视送给了一个朋友。
9. since 也可以表示 because
You can also use since in this way:
Since it’s late and we’re tired, let’s get a taxi home.
既然已经很晚了，而且我们也累了，我们坐出租车回家吧。
这里：
since = because
所以：
as / since / because
在某些情况下都可以表示：
因为 / 由于 / 既然
10. as (= because) 和 when 的区别
这也是非常容易混淆的地方。
看下面两个句子：
as = because
David wasn’t in the office as he was on holiday. (= because he was on holiday)
David 不在办公室，因为他正在休假。
这里表达的是：
原因
逻辑：
he was on holiday ↓ therefore ↓ he wasn’t in the office
所以：
as = because
when = during the time
David lost his passport when he was on holiday. (= during the time he was away)
David 度假的时候丢了护照。
这里不是在解释：
“为什么丢护照”
而是在说明：
“什么时候丢的护照”
所以：
when = 在……的时候
11. 再比较一组
as = because
As they lived near us, we used to see them quite often. (= because they lived near us)
因为他们住在我们附近，所以以前我们经常见到他们。
逻辑：
lived near us ↓ because ↓ saw them often
when = at the time
When they lived near us, we used to see them quite often. (= at the time they lived near us)
当他们住在我们附近的时候，我们以前经常见到他们。
这里重点不是原因，而是：
那段时间
也就是说：
在他们住在我们附近的那段时期，我们经常见面。
12. 同一个 as，三个常见中文意思
这一单元中的 as 最重要的是不要机械翻译。
根据上下文，它主要有三种理解方式。
① 当……的时候
强调：
两个动作同时发生
例如：
As I walked along the street, I looked in the shop windows.
当我沿着街道走的时候，我看着商店橱窗。
② 随着……
强调：
两个事情同时逐渐变化
例如：
As the day went on, the weather got worse.
随着时间推移，天气变得越来越糟。
③ 因为……
强调：
原因
例如：
As I was hungry, I decided to eat something.
因为我饿了，所以我决定吃点东西。
13. 如何判断 as 到底是什么意思
看到：
as + subject + verb
不要马上翻译。
先判断两个句子之间是什么逻辑关系。
情况 1：同时发生
如果两个动作同时发生：
as = 当……的时候
例如：
As I was driving, I listened to a podcast.
我开车的时候听了播客。
情况 2：一起变化
如果两个事情随着时间同时变化：
as = 随着……
例如：
As I got older, I became more patient.
随着年龄增长，我变得更有耐心了。
情况 3：因果关系
如果前面的内容解释后面的原因：
as = because
例如：
As I was tired, I went to bed early.
因为我累了，所以我很早就睡了。
14. as 和 because 的区别
语法上：
as = because
但在实际表达中，because 通常比 as 更直接、更明确。
例如：
I went home early because I was tired.
我提前回家了，因为我累了。
这个原因非常明确。
而：
As I was tired, I went home early.
因为我累了，所以提前回家了。
语气通常更像是在提供：
背景原因
因此日常口语中，如果你只是想清楚表达“因为”，优先掌握：
because
会更容易。
15. 常见错误：as 和 when
如果两个事情有明显先后顺序，通常使用：
when
例如：
✅ When I arrived at the office, I turned on my computer.
我到办公室后，打开了电脑。
时间线：
arrived ↓ turned on my computer
不要因为中文都是“当……的时候”就机械使用 as。
如果两个动作同时进行：
✅ As I walked to the office, I listened to English.
我走去办公室的时候听英语。
这里：
walking + listening
同时发生。
16. 日常场景例句
开车
As I drove to work, I listened to an English podcast.
我开车上班的时候听英语播客。
工作
As I was writing code, my colleague called me.
我正在写代码的时候，同事给我打了电话。
回家
As I was leaving the office, it started to rain.
我正要离开办公室的时候，开始下雨了。
学习
As my English improved, I became more confident.
随着我的英语水平提高，我变得越来越自信。
原因
As I was tired, I decided to take a break.
因为我累了，所以我决定休息一下。
17. 最终思维模型
as = at the same time
两个动作：
同时发生
结构：
as + subject + verb
例如：
As I drove home, I listened to music.
我开车回家的时候听音乐。
核心：
A 和 B 同时进行
just as = exactly at that moment
核心：
恰好就在那个时候
例如：
Just as I sat down, the phone rang.
就在我刚坐下的时候，电话响了。
as = 随着
两个事情：
同时逐渐发展 / 变化
例如：
As the day went on, the weather got worse.
随着时间推移，天气越来越糟。
as = because
核心：
原因
例如：
As I was hungry, I decided to eat.
因为我饿了，所以我决定吃东西。
18. 最后压缩成四个公式
as + 两个同时发生的动作 = 当……的时候
just as + 动作 = 恰好在……的时候
as + 两个同时变化的事情 = 随着……
as + 原因 = because / 因为……
as 和 when 最关键的区别
As I drove home, I listened to music.
两个动作同时发生：
as
而：
When I got home, I had something to eat.
先到家，再吃东西：
when
所以可以记住：
as → 同时
when → 可以表示先后关系
as = because 和 when
David wasn’t in the office as he was on holiday.
这里回答：
Why?
为什么不在办公室？
Because he was on holiday.
所以：
as = because
而：
David lost his passport when he was on holiday.
这里回答：
When?
什么时候丢的？
When he was on holiday.
所以：
as → Why? → because
when → When? → 时间