第 10 课 · 第 1 阶段: 基础
“can / could” 表示能力
初级Ability with “can / could”
构成与用法
can/could + 动词 — 能做的事，或过去能做的事
1.形式
Can + 动词原形（不加 to）。Can 是情态动词：所有主语都用同一个形式，永远不加 -s，疑问句也不用 do。
| 例句 | |
|---|---|
| 肯定式 | I / you / he / she / we / they can swim. |
| 否定式 | can't (= cannot, 连写成一个词) swim |
| 疑问式 | Can you swim? · What can you see? |
| 简略回答 | Yes, I can. / No, I can't. |
听辨 can 和 can't：肯定句中 can 弱读成 /kən/，重音落在后面的动词上（I can SWIM）。Can't 总是重读：英式 /kɑːnt/，美式 /kænt/——I CAN'T swim。
2.什么时候用
1. 能力和技能——会做某事
My grandma can speak French.
我奶奶会说法语。
I can't ride a motorbike.
我不会骑摩托车。
2. 某种情况下的可能性——条件允许的时候
You can see the whole city from the rooftop.
从楼顶可以看到整座城市。
We can't go out — it's pouring.
我们出不去——外面下着大雨。
3. 请求、给予和拒绝许可
Can I sit here?
我可以坐这儿吗？
You can't park in front of the gate.
你不能把车停在大门前。
4. 请别人做某事（非正式）
Can you pass me the salt?
你能把盐递给我吗？
3.can see、can hear…
和感官动词 see、hear、smell、taste、feel 以及 remember、understand 连用时，英语常用 can 而不用进行时。
I can hear music next door.
我能听到隔壁有音乐声。（不说：I'm hearing）
Can you smell something burning?
你闻到有什么东西烧焦了吗？
4.过去：could / couldn't
Could = 过去的一般能力（在一段时间里都能做某事）。Couldn't = 不能做某事。
She could read when she was four.
她四岁就会读书了。
I couldn't sleep last night. It was too hot.
我昨晚睡不着，天太热了。
要表示某一次成功做成了某件具体的事，用 was / were able to 或 managed to，不用肯定的 could：
The exam was hard, but I managed to finish it.
考试很难，但我还是做完了。（不说：I could finish it）
The fire spread quickly, but everyone was able to get out.
火势蔓延得很快，但所有人都逃出来了。
否定句中，couldn't 两种情况都可以用：I tried, but I couldn't open the jar.
5.Can 没有将来时和完成时
Can 只有两种形式：can 和 could。没有 “will can”、“to can” 或 “have could” 这样的说法。需要这些形式时，用 be able to——见下一课。
One day I'll be able to speak English fluently.
总有一天我能说一口流利的英语。
I'd love to be able to cook.
我真希望自己会做饭。
6.常见错误
He cans play the guitar.He can play the guitar.
can 永远不加 -s。
I can to swim.I can swim.
can 后面不加 to。
Do you can help me?Can you help me?
can 不和 do 一起用。
I will can come tomorrow.I'll be able to come tomorrow.
将来时用 will be able to。
She can sings well.She can sing well.
can 后面用原形。
例句
- My little sister is five, but she can swim very well.
- Sorry, I can't hear you. The music is too loud.
- Can you speak Japanese?
- A: Can your dad cook? B: Yes, he can. He makes great fish soup.
