第 25 课 · 第 2 阶段: 常用词：代词、冠词、介词
连接词：and / but / or / so / because
初级Linking words: and / but / or / so / because
构成与用法
and 表示补充，but 表示转折，or 表示选择，so 表示结果，because 表示原因
1.五个基本连词
这些词用来连接两个单词、两个短语或两个分句（句子的两个部分）。每个词表示两部分之间的一种不同关系。
| 连词 | 意思 | 例句 |
|---|---|---|
| and | 补充信息 | I had pho and my sister had bun cha. |
| but | 转折、对比 | The room is small but clean. |
| or | 选择 | Do you want tea or coffee? |
| so | 结果 | It was late, so we took a taxi. |
| because | 原因 | We took a taxi because it was late. |
2.每个词的用法
1. And——连接两个相似的意思，补充信息
Lan plays the guitar and sings.
阿兰会弹吉他，也会唱歌。
I got up, had a shower and went to work.
我起床、洗了个澡，然后去上班。（列举：用逗号隔开，最后一项前加 and）
2. But——两个相反的意思，或者出乎意料的事
The food was cheap but delicious.
饭菜很便宜，但很好吃。
I called him twice, but he didn't answer.
我给他打了两次电话，但他没接。
3. Or——表示选择；在否定句里连接两个都被否定的事物；在指令后面表示“不然……”
Shall we eat in or go out?
我们在家吃还是出去吃？
I don't eat meat or fish.
我不吃肉，也不吃鱼。（否定句中用 or）
Put on a jacket, or you'll catch a cold.
穿上外套，不然你会感冒的。（or = 不然）
4. So——放在结果前面
My phone died, so I couldn't call you.
我的手机没电了，所以没法给你打电话。
It's going to rain, so take an umbrella.
要下雨了，所以带把伞吧。
5. Because——放在原因前面，回答 Why? 这个问题
I couldn't call you because my phone died.
我没法给你打电话，因为我的手机没电了。
Why are you laughing? — Because this video is so funny!
你笑什么？——因为这个视频太搞笑了！
3.So 还是 because？
同一件事可以用两种方式说：原因 + so + 结果，或者 结果 + because + 原因。用错了词，意思就错了。
It was very hot, so we went to the beach.
天很热，所以我们去了海边。
We went to the beach because it was very hot.
我们去了海边，因为天很热。
中文常说“因为……所以……”，一句话里两个词都用，但英语只用一个：Because I was sick, I stayed in bed. 或 I was sick, so I stayed in bed. 不要说 “Because I was sick, so I stayed in bed”。
4.逗号和位置
- so 前面通常有逗号：It was late, so we went home.
- but 连接两个较长的分句时，前面常加逗号；连接两个简短的词时，不加逗号：small but clean.
- Because 在句子中间时通常不用逗号。如果 because 放在句首，就在原因后面加逗号：Because it was late, we went home.
- 两部分的主语相同时，and / but / or 后面的第二个主语可以省略：She lives in Hue and works in Da Nang.
- 在书面语中，单独一句 “Because I was tired.” 不是完整的句子。但在对话中，用 Because… 回答 Why? 是完全自然的。
- 用 And / But / So 开头在口语和非正式书面语中很常见；正式书面语中要少用。
5.时间连词：when, before, after, until
这些词按时间把两个动作连起来：哪个先发生，哪个后发生，或者同时发生。
| 连词 | 意思 | 例句 |
|---|---|---|
| when | 在……的时候 | My dog barks when someone rings the bell. |
| before | 在……之前 | Wash your hands before you eat. |
| after | 在……之后 | I'll call you after I finish work. |
| until | 直到……为止 | Stay in bed until you feel better. |
We left before the film ended.
电影还没结束我们就走了。
After I graduated, I moved to Saigon.
毕业后，我搬到了西贡。（时间连词放在句首 → 加逗号）
Don't open your presents until everyone arrives.
等所有人都到了再拆礼物。
谈论将来时，when / before / after / until 后面用一般现在时，不用 will：I'll call you when I get home（不说：when I will get）。见“表将来的时间状语从句”一课。
6.常见错误
I was tired, because I went to bed early.I was tired, so I went to bed early.
第二部分是结果 → 用 so。
He missed the bus so he got up late.He missed the bus because he got up late.
第二部分是原因 → 用 because。
Do you want rice but noodles?Do you want rice or noodles?
表示选择 → 用 or。
Because it rained, so we stayed in.Because it rained, we stayed in. / It rained, so we stayed in.
because 和 so 只能用一个，不能两个都用。
I'll tell you when I will know.I'll tell you when I know.
表示将来时，when 后面用一般现在时。
例句
- I like tea, but my husband prefers coffee.
- Is your new teacher a man or a woman?
- It was raining, so we stayed at home.
- We stayed at home because it was raining.
