a. for what reason, purpose, or cause?: why are you here?. b. (used in indirect questions): tell me why you're here. The meaning of WHY is for what cause, reason, or purpose. How to use why in a sentence. /waɪ/ IPA guide Other forms: whys Definitions of why noun the cause or intention underlying an action or situation, especially in the phrase `the whys and wherefores' synonyms: wherefore When we ask for reasons in speaking, we can use the phrase why is that? In informal conversations we often say why’s that?: … When we ask for reasons in speaking, we can use the phrase why is that? In informal conversations we often say why’s that?: … You use why in questions when you ask about the reasons for something. Why hasn't he brought the bill? Why didn't he stop me? Why can't I remember the exact year we married? The word why is essential for seeking understanding, clarifying reasons, and expressing curiosity or surprise. Its applications span everyday conversation, academic exploration, and storytelling. Adding do is in a category of mistakes that is very common for English learners. It's a tell tale sign that English is someone's second language and even functionally fluent people do this. Why do is used with plural subjects, while why does is used with singular subjects. Therefore, the choice between the two depends on the subject of the sentence. WHY definition: for what? for what reason, cause, or purpose?. See examples of why used in a sentence.