1. used to indicate possibility
表示可能性
It could rain later.
稍後可能會下雨。
He could be at home.
他可能在家。
Could Meaning（定義、用法、例句與發音）
could
modal
快速理解
What does "Could" mean?What are 2-3 core uses of "Could"?
「could」是「can」的過去式，主要用於表達可能性、能力或提出請求與建議。
- 1
過去的能力
EN: I could run fast when I was young.
翻譯: 我年輕時可以跑得很快。
- 2
可能性
EN: It could rain later.
翻譯: 稍後可能會下雨。
- 3
禮貌的請求
EN: Could you help me with this?
翻譯: 你可以幫我這個忙嗎？
- 4
建議
EN: You could try restarting the computer.
翻譯: 你可以試著重新啟動電腦。
小提醒：注意：「could」用於現在或未來的可能性時，比「might」或「may」的語氣更不確定。
發音（How to Pronounce "Could" in English）
How to pronounce "Could" in English?"Could" US vs UK pronunciation
點擊下方的 US / UK 按鈕可播放發音。
Real-life Examples of "Could" from YouTube Videos
South Korea would accept Trump-Kim deal to freeze North Korea’s nuclear programme | BBC News
BBC News
“>>. You've stopped radio broadcasts into North Korea. These were one of the very few ways that North Koreans could get information from outside the country.”
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Definitions（定義）
What are the definitions of "Could"?How does "Could" change by context?
2. used to make a polite request
用於提出禮貌的請求
Could you pass the salt, please?
請問你可以把鹽遞給我嗎？
Could I borrow your pen for a moment?
我可以借用一下你的筆嗎？
3. used to express ability in the past
表示過去的能力
When I was young, I could run very fast.
我年輕的時候可以跑得很快。
She could speak three languages by the age of ten.
她十歲時就會說三種語言了。
4. used in conditional sentences to express a hypothetical situation
用於條件句中，表達假設性的情況
If I had more time, I could help you.
如果我有更多時間，我就能幫你了。
We could go to the beach if the weather is nice.
如果天氣好，我們就可以去海邊。
5. used to make a suggestion
用於提出建議
We could try that new Italian restaurant.
我們可以去試試那家新開的義大利餐廳。
You could ask your teacher for help.
你可以向你的老師尋求幫助。
Grammar & Patterns（句型）
What are common sentence patterns for "Could"?How to make natural sentences with "Could"?
| Pattern | Meaning | Example |
|---|---|---|
| could + base verb | 表示能力（過去） | I could swim when I was five. (我五歲時就會游泳了。) |
| could + base verb | 表示請求（禮貌） | Could you open the window? (可以請你開窗嗎？) |
| could + base verb | 表示可能性 | It could rain later. (稍後可能會下雨。) |
| could + base verb | 表示建議 | You could try restarting the computer. (你可以試著重啟電腦。) |
| could have + past participle | 表示過去未實現的可能性 | She could have been a great artist. (她本可以成為一位偉大的藝術家。) |
| could not (couldn't) + base verb | 表示過去無法做到 | I couldn't find my keys yesterday. (我昨天找不到我的鑰匙。) |
用法說明
How is "Could" different from similar structures?What usage mistakes are common with "Could"?
could have done vs. could do
- could have + 過去分詞 表示對過去未發生或未知結果之事的推測或假設，常帶有遺憾或批評的語氣。
- could + 動詞原形 表示對現在或未來能力、可能性的描述，或對現在情況的推測。
- 兩者皆可談論可能性，但時間指向不同，且 could have done 更強調與過去事實的對比。
對比例句： EN: She could have finished the project if she had more time. 翻譯: 如果她有更多時間，她本來可以完成這個專案的。
EN:She could finish the project by tomorrow.
翻譯:她有可能在明天之前完成這個專案。
總結建議
談論過去未實現的可能性或表達遺憾時使用 could have done，描述現在或未來的一般可能性或能力時則用 could do。
易混淆對比
What is the difference between "Could" and similar words?How to choose "Could" vs alternatives?
could vs can
「could」常表示可能性或委婉的請求，而「can」則表示能力或較直接的許可。
could vs would
「could」強調可能性或能力，而「would」則強調意願、習慣或假設結果。
could vs might
「could」和「might」都表示可能性，但「might」的不確定性通常更高，且不用於表示能力。
口語用法
How is "Could" used in spoken English?What is the spoken vs formal difference for "Could"?
引述
在轉述他人的話語或想法時，常使用「could」來表示間接引述，語氣比「can」更委婉、不那麼直接。 EN: She said she could help us tomorrow. 翻譯: 她說她明天可以幫忙我們。
EN:I thought I could finish it by Friday.
翻譯:我本來以為我週五前能完成。
語氣強調
在口語中，可透過重音或語調強調「could」，來表達強烈的驚訝、懷疑或惱怒。 EN: You could have told me earlier! 翻譯: 你大可以早點告訴我啊！
EN:How could you forget our anniversary?
翻譯:你怎麼能忘記我們的紀念日？
停頓填充
在思考或組織語句時，「could」有時會作為一個短暫的停頓填充詞，後面常接「be」、「have」等，用來提出一個可能的想法或推測。 EN: Well, it could… be a problem with the software. 翻譯: 嗯，這可能…是軟體的問題。
EN:The delay could… have been caused by the weather.
翻譯:延誤可能…是天氣造成的。
正式寫作注意：在學術或正式商業寫作中，應避免將「could」用作停頓填充詞，並確保其用法清晰對應能力、可能性或禮貌請求，以保持文體的嚴謹性。
常見短語
What common collocations use "Could"?What fixed phrases with "Could" should I remember?
could you
could you [verb]
用於禮貌地提出請求或詢問
could be
could be [adjective/noun]
表示可能性或潛在的狀態
could have
could have [past participle]
表示過去未實現的可能性或對過去的推測
could do with
could do with [noun/gerund]
表示需要或想要某物
could not help
could not help [gerund]
表示忍不住做某事
could well
could well [verb]
表示某事很有可能發生
could do worse than
could do worse than [verb/noun]
建議某個行動或選擇是好的或明智的
常見錯誤
What are common mistakes with "Could"?Which "Could" sentences look correct but are wrong?
×I could to speak English when I was young.
✓I could speak English when I was young.
「could」是情態動詞，後面直接接動詞原形，不加「to」。
×If you studied harder, you could pass the exam yesterday.
✓If you had studied harder, you could have passed the exam yesterday.
描述與過去事實相反的假設時，應使用「could have + 過去分詞」來表示過去有能力做但未做。
×Could you please to close the door?
✓Could you please close the door?
在禮貌請求句型「Could you please...」中，「please」後面直接接動詞原形，不加「to」。
×I couldn't bought the ticket because it was too expensive.
✓I couldn't buy the ticket because it was too expensive.
情態動詞「could」的否定形式「couldn't」後面接動詞原形，動詞不因時態而變化。
×This could happens if we're not careful.
✓This could happen if we're not careful.
「could」表示可能性時，後面接的動詞永遠用原形，不因主詞單複數或時態而加「s」。
×I'm not sure, but he could is at home now.
✓I'm not sure, but he could be at home now.
「could」後面接狀態動詞「be」時，必須用原形「be」，而不是「is/am/are」。
詞形變化
What are the word forms of "Could"?What are tense/participle forms of "Could"?