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Grammar point
A2Very commonModal VerbsNeutralElementary

Vietnamese 'phải' Usage (must / have to)

'phải' is commonly used to express obligation or necessity, meaning "must" or "have to". It is essential for learners to master.

Quick explanation

Quick explanation

'phải' is commonly used to express obligation or necessity, meaning "must" or "have to". It is essential for learners to master.

English meanings

  • must
  • have to

Grammar pattern

S + phải + V

Examples

1

Tôi phải đi làm.

I must go to work.

2

Bạn phải học chăm chỉ.

You have to study hard.

How to use it

'phải' indicates a strong obligation or necessity, stronger than 'nên'. It usually refers to duties, rules, or unavoidable actions.

  • S + phải + V expresses necessity to do something.
  • For suggestions, use 'nên'.
  • For needing something, use 'cần'.

Compared with English

Compared with English

In English, "must" or "have to" express obligation. Vietnamese 'phải' corresponds closely to these, unlike 'nên' which is more like "should".

Common mistakes

Tôi phải cà phê.

Tôi cần cà phê.

To express needing something, use 'cần' + noun, not 'phải' + noun.

Bạn phải nghỉ ngơi một chút.

Bạn nên nghỉ ngơi một chút.

For a suggestion to rest, 'nên' is more natural than 'phải'.

Commonly confused grammar

Practice

Multiple choice

Which meaning best matches 'phải'?

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  • must
  • can
  • like

Answer: must

Explanation: 'phải' expresses obligation or necessity.

Fill in the blank

Fill in the blank: Tôi ____ đi làm.

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Answer: Tôi phải đi làm.

Explanation: S + phải + V expresses necessity to do something.

English to Vietnamese

Translate "I must go to work." into Vietnamese.

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Answer: Tôi phải đi làm.

Explanation: Use phải in the same structure as the example.

True or false

True or False: Tôi phải cà phê.

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Answer: False

Explanation: To express needing something, use 'cần' + noun, not 'phải' + noun.

Correction

Correct this sentence: Tôi phải một quyển sách.

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Answer: Tôi cần một quyển sách.

Explanation: Use 'cần' to express needing an object.

Related grammar