why

1 of 4

adverb

: for what cause, reason, or purpose
why did you do it?

why

2 of 4

conjunction

1
: the cause, reason, or purpose for which
know why you did it
that is why you did it
2
: for which : on account of which
know the reason why you did it

why

3 of 4

noun

plural whys
1
: reason, cause
wants to know the whys and wherefores
2
: a baffling problem : enigma

why

4 of 4

interjection

used to express mild surprise, hesitation, approval, disapproval, or impatience
why, here's what I was looking for

Examples of why in a Sentence

Adverb Why did you quit your job? Why is the sky blue? Why didn't you call me? Why didn't I think of that? “I can't go out tonight.” “Why not?” Conjunction I know why he did it. It's easy to see why she fell in love with him. He's a very good player. That's why he made the team. The reason why they succeeded is obvious. They worked really hard. Give me one good reason why I should stay. Noun asked the whys behind the surprising decision how one decides that a certain he or she is “the one” is one of the great whys of life Interjection why, what a strange thing to say!
Recent Examples on the Web
Adverb
So that’s the how and why; the real — unfair — question is whether the song comes close to measuring up to the Beatles or their collective solo works’ towering legacy. Jem Aswad, Variety, 2 Nov. 2023 Several wanted to know why the Chinese airship was allowed to float all the way to the Atlantic Ocean before it was shot down. Ellen Nakashima, Washington Post, 11 Feb. 2023 See all Example Sentences for why 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'why.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

Adverb

Middle English, from Old English hwȳ, instrumental case of hwæt what — more at what entry 1

First Known Use

Adverb

before the 12th century, in the meaning defined above

Conjunction

before the 12th century, in the meaning defined at sense 1

Noun

13th century, in the meaning defined at sense 1

Interjection

1519, in the meaning defined above

Time Traveler
The first known use of why was before the 12th century

Dictionary Entries Near why

Cite this Entry

“Why.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/why. Accessed 24 May. 2024.

Kids Definition

why

1 of 4 adverb
(ˈ)hwī How to pronounce why (audio)
(ˈ)wī
: for what cause or reason
why did you do it

why

2 of 4 conjunction
1
: the cause or reason for which
know why you did it
2
: for which : on account of which
the reason why she did it

why

3 of 4 noun
ˈhwī,
ˈwī
plural whys
: reason entry 1 sense 1a
explained the whys and wherefores of the sudden price increase

why

4 of 4 interjection
(ˌ)wī,
(ˌ)hwī
used to express surprise, indecision, approval, disapproval, or impatience
why, I didn't know that

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