What does why mean?
Why is an English question word used to ask about the reason, cause, or purpose of an action, event, or situation. It is commonly used in direct questions, as in “Why are you waiting?”, and can also introduce an explanatory clause, as in “I understood why the meeting had been cancelled.” The word may be used as a noun when referring to a reason or motive, especially in expressions such as “the whys and wherefores.” Its pronunciation is simple and consistent in both British and American English, with the vowel sound heard in “my” and “high.” Why is useful because it can seek information, request clarification, express puzzlement, or invite an explanation. Although it resembles the closely related interrogative words who, what, which, and whether, why has a distinctive function: it focuses on causes and purposes rather than identity, things, choices, or alternatives.
Asks for the reason, purpose, or cause of something.
"Why did the lights go out?"
This is the most common modern use of the word.
Introduces a clause that states a reason or explanation.
"I could see why he had changed his mind."
This use is especially common after verbs such as understand, explain, know, and see.
A reason, motive, or purpose for something.
"They discussed the whys and wherefores of the decision."
The noun sense is less frequent than the interrogative use and often appears in formal or idiomatic expressions.
The plural whys is used when referring to multiple reasons or motives.
"Every decision has its advantages and its whys."
Why began as an old English question word for cause and remains one of the simplest ways to ask for an explanation.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does why come from?
The word descends from Old English interrogative forms such as hwi and hwȳ, which asked about reason or cause. It is cognate with other English interrogatives, including who, what, which, and whether, and developed into the modern form why. The word has continued to function both as a question and as an explanatory connective, with the noun sense developing later from its use to refer to reasons.
Related word forms
How why is actually used
Why is neutral in register. “Why not?” can sound informal but is widely accepted in both British and American English. The noun sense is less common and is especially natural in phrases about reasons or motives.
Easily confused with why
Why asks for a reason, whereas because introduces the answer to that question.