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

Etymology

Origin of why

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

Example Sentences

See Examples For:

why whys

“I think it is,” Smith replied, “I don’t think there’s any question about it. And that’s why I spoke out against it because it’s utterly ridiculous.”

From Los Angeles Times ● Aug. 18, 2026

"That is why the police had registered some cases against him."

From BBC ● Aug. 18, 2026

Michael Kramer, portfolio manager at Mott Capital Management, sees a few reasons why it could be wise to buy some hedges.

From MarketWatch ● Aug. 18, 2026

I’m 23, and I understand why my generation is frustrated.

From The Wall Street Journal ● Aug. 18, 2026

“Uncle Max, why don’t we head down to Sandy June’s Legendary?”

From "Legendary Frybread Drive-In" by Cynthia Leitich Smith

"Why did no-one tell the young people to get out? Why did the council not make the proper checks? There are too many whys."

From BBC ● Jan. 9, 2026

At least some of the whys of cheating can be tamped down, resulting in less cheating, Pope said.

From Los Angeles Times ● Sep. 27, 2025

Pregnancy is some of the most personal experiences a woman can have – so to constantly be speculating about all the whys strips a woman of her right to privacy.

From Salon ● Nov. 3, 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

“What you should know is that I’m concerned. Knowing what I was like at your age, I’m real curious about the whys of the trouble you been in.”

From "Clean Getaway" by Nic Stone