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Meaning & use

why

adverb, noun·Everyday

Last updated

UK/waɪ/
US/waɪ/

Meanings

  1. adverb

    For what reason or purpose; used to ask about the cause of something.

    Grammar: Used to begin direct questions: Why did you call? It can also introduce indirect questions: I wonder why she left.

    Patterns

    • why + verb
    • why + auxiliary + subject + verb

    Why are you late?

    She asked why I was upset.

    Why did the alarm go off?

  2. adverb

    For which reason; used to give or ask about the reason for something.

    Grammar: Often used in indirect questions or after expressions like 'That is' or 'I don't know'.

    Patterns

    • that is why + clause
    • the reason why + clause

    That is why I left early.

    I don't know why he resigned.

    The reason why she called is still unclear.

  3. adverbinformal

    Used to express surprise, disagreement, or as a response showing that something is obvious.

    Grammar: Used as a response or interjection, often with a question mark or exclamation.

    Patterns

    • why, ...

    Why, that's wonderful news!

    Why, of course I remember you.

    Why not? It sounds like fun.

  4. nouncountable

    The reason or explanation for something.

    Grammar: Usually used in the plural, as in 'the whys and wherefores'.

    Patterns

    • the whys and wherefores

    We need to understand the whys of the decision.

    She explained the whys and wherefores of the policy.

Common combinations

why not
Why not join us for dinner?
that's why
That's why I always carry an umbrella.
the reason why
The reason why he left is a mystery.
why on earth
Why on earth did you do that?
why bother
Why bother cooking when we can order in?

Synonyms and how they differ

how come
Informal and often used in direct questions; it cannot be used in indirect questions the same way 'why' can.
wherefore
Old-fashioned or literary; it means 'for what reason' but is rarely used in modern English.

Commonly confused: why or how?

why vs how

How asks about manner or method, while why asks about reason or cause. Compare 'How did you fix it?' (method) with 'Why did you fix it?' (reason).

Practice

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