第 105 課 · 第 9 階段: 連線觀點
As = when / because
中級構成與用法
As I was leaving, the phone rang. As it was late, we took a taxi.
1.as 的兩種意思
as 引導從句時（as + 主語 + 動詞），通常有兩種意思之一：when / while（當……時）或 because（因為）。上下文和動詞時態可以幫你區分。
| 意思 | 通常搭配 | 例句 |
|---|---|---|
| 時間（= when / while） | 正在進行的動作，常用過去進行時 | As I was leaving, the phone rang. |
| 原因（= because / since） | 聽者已經知道或能猜到的原因 | As it was late, we took a taxi. |
As 還有別的用法：as a teacher（作為——見“Like 與 as”一課）、as tall as（比較）。這一課只講 as 連線兩個從句的用法。
2.As = when、while
As 表示兩件事同時發生。較長的背景動作常用過去進行時，在這期間發生的短暫動作用一般過去時（見“過去進行時”一課）。Just as = 恰好在那一刻。
As I was walking to work, I saw an accident.
我走路去上班的時候，看到了一起事故。
The phone rang just as I was getting into the shower.
我正要進去洗澡，電話就響了。
My hands were shaking as I opened the letter.
我拆信的時候手一直在抖。
兩件事一起變化時也用 as：
As we got closer to the beach, we could hear the waves.
離海灘越來越近，我們聽到了海浪聲。
As the evening went on, the restaurant got busier.
隨著夜色漸深，餐廳越來越熱鬧。
表示人生中的一段時期或較長的一段時間時，不要用 as：When I was a child, I lived in Hue（不說：As I was a child… —— 聽者會理解成“因為我是個孩子”）。
3.As = because
As（和 since）表示原因，通常是聽者已經知道的原因，或者不是重點的原因。as 從句常放在前面。當原因是主要資訊時——特別是回答 Why…? 的時候——用 because。as 表示“因為”在英式英語中很常見；美國人更常用 since 或 because。
As it was a public holiday, the banks were closed.
因為是公共假日，銀行都關門了。
As you're not busy, could you help me with this box?
既然你不忙，能幫我搬一下這個箱子嗎？
We ordered pizza as nobody wanted to cook.
因為沒人想做飯，我們就點了披薩。
Since you're here, let's start the meeting.
既然你來了，我們開會吧。（since = as）
中文習慣說“因為……所以……”。英語只用其中一個：As it was late, we took a taxi. / It was late, so we took a taxi. 不說 “As it was late, so we took a taxi”。
4.用 as、when、while 還是 because？
| 用於 | 例句 | |
|---|---|---|
| when | 某一時刻、一個短暫的動作或人生的一段時期 | When I was ten, we moved to Hue. |
| while | 在另一件事正在發生的過程中 | Someone called while you were out. |
| as | 兩件事同時發生或一起變化；講故事時常用 | As the bus pulled away, I realised I'd left my bag. |
| because | 原因是主要資訊 | I'm late because my alarm didn't go off. |
| as / since | 已知的原因，常放在句首 | As it's raining, let's stay in. |
有時 as 兩種理解都說得通。如果想表達得完全清楚，就用 while（時間）或 because（原因）。
As I was cooking, the lights went out.
我做飯的時候，突然停電了。（時間）
As I was cooking, I couldn't answer the phone.
我在做飯，沒法接電話。（時間或原因——兩種理解都可以）
As Huy was ill, he stayed at home.
因為阿輝病了，他待在家裡。（狀態 → 原因）
5.常見錯誤
As it was late, so we took a taxi.As it was late, we took a taxi.
as 和 so 不要一起用。
Like it was raining, we stayed home.As it was raining, we stayed home.
Like 不能表示“因為”。
As I was a child, I lived in Hue.When I was a child, I lived in Hue.
表示人生的一段時期用 when。
As I was cooking, I was cutting my finger.As I was cooking, I cut my finger.
短暫的動作用一般過去時。
Why did you leave early? — As I felt sick.Why did you leave early? — Because I felt sick.
回答 Why 用 because。
例句
- As I was walking home, it started to rain.
- As it was a holiday, the streets were very quiet.
- As I didn't have any cash, I paid by card.
- Minh arrived as we were having dinner.
