C1

S + can't have + V3 · S + mustn't + V0

can't have V3 khác mustn't have

Explanation

Hai cụm nghe gần nhau nhưng làm hai việc khác nhau. can't have V3 là phán đoán: tôi chắc việc đó KHÔNG xảy ra. mustn't V0 là cấm: bạn không được làm. Suy đoán phủ định về quá khứ luôn dùng can't have hoặc couldn't have, không dùng mustn't have. Bẫy thường gặp: Không dùng mustn't have cho suy đoán: He mustn't have finished ✗, He can't have finished ✓.

Examples

He can't have finished already.

Không thể nào ông ấy đã làm xong.

You mustn't touch the wiring.

Bạn không được chạm vào dây điện.

She couldn't have known about the change.

Cô ấy không thể nào biết về sự thay đổi đó.

Guests mustn't smoke in the corridor.

Khách không được hút thuốc ở hành lang.

Practice

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Learn “S + can't have + V3 · S + mustn't + V0” effectively

The grammar point “S + can't have + V3 · S + mustn't + V0” (can't have V3 khác mustn't have) is one of the key structures at CEFR 5. To use it fluently, you need to understand the contexts where it's used and practice regularly.

Study tip: read the examples aloud many times to build a natural reflex. Then try making your own sentences for your own situations. Use the audio button to hear and practice accurate pronunciation.

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