why

American  

[hwahy, wahy] / ʰwaɪ, waɪ /

adverb

1. for what? for what reason, cause, or purpose?.

   Why did you behave so badly?

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conjunction

1. for what cause or reason.

   I don't know why he is leaving.

2. for which; on account of which (usually after reason to introduce a relative clause).

   the reason why he refused to go.

3. the reason for which.

   That is why he returned.

noun

• whys
  plural

1. a question concerning the cause or reason for which something is done, achieved, etc..

   a child's unending hows and whys.

2. the cause or reason.

   the whys and wherefores of a troublesome situation.

interjection

1. (used as an expression of surprise, hesitation, etc., or sometimes a mere expletive).

   Why, it's all gone!

why British  

/ waɪ /

adverb

1. 1. for what reason, purpose, or cause?

      why are you here?

   2. ( used in indirect questions )

      tell me why you're here

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pronoun

1. for or because of which

   there is no reason why he shouldn't come

noun

1. (usually plural) the reason, purpose, or cause of something (esp in the phrase the whys and wherefores )

interjection

1. an introductory expression of surprise, disagreement, indignation, etc

   why, don't be silly!

Usage

See reason.

Other Word Forms

Noun Inflected Forms

• whys
  plural

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Etymology

Origin of why

First recorded before 900; Middle English; Old English hwī, hwȳ, instrumental case of hwæt what; cognate with Old Norse hvī

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Example Sentences

See Examples For:

why whys

This increase in storminess is why the storm-naming season begins in September each year.

From BBC ● Oct. 17, 2026

You can see why Olivia Rodrigo wanted to get dinner with him.

From Los Angeles Times ● Oct. 16, 2026

"I don't understand why a mom would buy a teenage boy a weapon like that," said Vanetsky.

From Barron's ● Oct. 16, 2026

How and why did the tide turn against this sticky substance?

From Slate ● Oct. 16, 2026

“Thanks. So, why should the Confederate flag be taken down?”

From "Split the Sky" by Marie Arnold

One note for Miles, like Billie Holiday, like Cindy says, that’s enough to understand all the whys and all the reasons why it’s sacred to be alive.

From Los Angeles Times ● May 25, 2026

"Ronaldo does things, but he does them knowing all the whys, and that's what impresses me. I'm convinced he'll continue for another one, two, or even three years," said his former Al-Nassr coach Luis Castro.

From BBC ● Feb. 5, 2025

So this book goes into all the whys.

From Salon ● Oct. 31, 2023

Physicists believe that there must have been some primordial imbalance that allowed matter to dominate the universe, yet the hows and whys remain open questions.

From Scientific American ● Sep. 27, 2023

I do not want to hear your whys, Uhmma insists.

From "A Step from Heaven" by An Na

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