shéi?
Who?
可以吗?
Is it okay?
This is a simple question: 可以 (kěyǐ) "can/okay" + 吗 (ma) question particle. It's a fixed expression for seeking approval.
可以
kěyǐ
It's okay. — Shorter, without the question.
可以吗?
kěyǐ ma?
Is it okay? — Standard question form.
可以不可以?
kěyǐ bù kěyǐ?
Is it okay or not? — More colloquial, adds emphasis.
我可以借你的书吗?
Wǒ kěyǐ jiè nǐ de shū ma?
Can I borrow your book?
当然可以!
Dāngrán kěyǐ!
Of course you can!
Appropriate
Avoid when
You can say 可以吗? (kěyǐ ma?). It literally means 'Can it?' or 'Is it okay?' and is used to ask for permission or approval.
It is pronounced kěyǐ ma? The third tone on kě and yǐ often becomes a half-third tone in fast speech, and ma is neutral.
Use 可以吗? when you want to check if something is acceptable or allowed, such as asking to borrow something or suggesting a time. It is polite and casual.
Tomyo
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