English Reference
adverb · conjunction · noun · interjection

why

adv. · conj. · n. · interj.
US /ˈhwaɪ/ UK /wˈaɪ/ why UK spelling why's, why's

  1. 01 A1 Beginner

    adv.you use this to ask for the reason or purpose of something.

    adv.used as an interrogative adverb to inquire about the cause, reason, or purpose of an action.

    Simple

    Why did you decide to move to a different city?

    In context

    Why did the board of directors choose to ignore the consultant's warnings despite the clear evidence of financial risk?

    Pitfall
    Why you are late? Why are you late?

    In direct questions, the verb or auxiliary verb must come before the subject after 'why'.

    how comefor what reason
  2. 02 A2 Elementary

    conj.the reason for which something happens.

    conj.used as a relative adverb to introduce a subordinate clause that explains a reason.

    Simple

    I do not know why the car is making that strange noise.

    In context

    The primary reason why the project failed was a lack of communication between the design and engineering departments.

    the reason that
  3. 03 B2 Upper Intermediate

    n.the reason or explanation for something.

    n.the underlying reason or cause for a situation, often paired with 'how' or 'wherefore'.

    Simple

    The book explains the why and how of the French Revolution.

    In context

    Before we implement the new policy, we must clearly articulate the why behind these structural changes to the staff.

  4. 04 C1 Advanced LiteraryArchaic

    interj.a word used to show you are surprised or to add emphasis to what you are saying.

    interj.used to express mild surprise, hesitation, or to emphasize a following statement.

    Simple

    Why, I had no idea you were planning to visit us today.

    In context

    Why, it has been nearly twenty years since we last walked through these gardens together.

    Usage

    Often placed at the beginning of a sentence to signal a shift in thought or a reaction to new information.


From Middle English why, from Old English hwȳ (“why”), from Proto-Germanic hwī (“by what, how”), from Proto-Indo-European kʷey, instrumental case of kʷís (“who”), kʷid (“what”). Cognate with Old Saxon hwī (“why”), hwiu (“how; why”), Middle High German wiu (“how, why”), archaic Danish and Norwegian Bokmål hvi (“why”), Norwegian Nynorsk kvi (“why”), Swedish vi (“why”), Faroese and Icelandic hví (“why”), Latin quī (“why”), Doric Greek πεῖ (peî, “where”), Ukrainian чи (čy, “if”), Polish czy, Czech či (“or”), Serbo-Croatian či (“if”). Compare Old English þȳ (“because, since, on that account, therefore, then”, literally “by that, for that”). See thy.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin ine-pro *kʷey
Level A1 · Beginner
Frequency Very common
Updated