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 week saw the launch of the second phase of an independent inquiry, led by former Cabinet minister Baroness Morris, into why children from those communities lag behind their peers at school.

From BBC ● Nov. 13, 2026

The latest study suggests that understanding why younger adults are developing the disease more frequently could also help explain what is happening in older populations.

From Science Daily ● Nov. 12, 2026

"We don't know how this is going to unfold or what measures will be taken to recover public money. That's why we're going to remain vigilant," he said.

From Barron's ● Nov. 12, 2026

Saying why, or even providing a chronology to this progressively absorbing and edifying Ewing-Grady film, would be to undermine its architecture.

From The Wall Street Journal ● Nov. 12, 2026

Aunt J looks at Arlo and me, as if to ask why we didn’t give her a heads-up.

From "Split the Sky" by Marie Arnold

I get to do songs that I wasn’t able to do on Olivia’s set and really get into the whys of it all,” she says.

From Los Angeles Times ● Sep. 29, 2026

You don't know the whos and the whats and the whys of how we came to be and how our relationship fell apart to get us to that point.

From Salon ● Oct. 26, 2024

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

This thoughtfully inclusive guide makes a great starting place, supplying the hows and whys of creating an edible garden to further our personal resilience, strength and healing.

From Seattle Times ● May 12, 2023

“You mean all the whos, whats, whys, whens, and wheres? Yes, I suppose I have. And thanks to the Depression, I’ve also been promoted to copy editor, typesetter, and coffee maker extraordinaire.”

From "Moon Over Manifest" by Clare Vanderpool

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