Delve into the comprehensive guide for why in The Academic Glossary. This entry covers its deep etymology, various definitions, real-world usage examples in literature, media, and daily discourse, and common idiomatic phrases, aiding a complete understanding. a. for what reason, purpose, or cause?: why are you here?. b. (used in indirect questions): tell me why you're here. Iran has brought days of relative calm in the Middle East to an end after launching what the US called a “surprise” attack in a striking change to the pattern of fighting. The meaning of WHY is for what cause, reason, or purpose. How to use why in a sentence. Why is it is commonly used to ask questions about a specific situation or action, while why it is is used to provide an explanation or reason for something. Human activities are driving the global warming trend observed since the mid-20th century. The greenhouse effect is essential to life on Earth, but human-made emissions in the atmosphere are trapping and slowing heat loss to space. Five key greenhouse gases are carbon dioxide, nitrous oxide, methane, chlorofluorocarbons, and water vapor. There are 16 meanings listed in OED's entry for the word why, three of which are labelled obsolete. See ‘Meaning & use’ for definitions, usage, and quotation evidence. When we ask for reasons in speaking, we can use the phrase why is that? In informal conversations we often say why’s that?: … Some philosophers conclude 'Why is there something rather than nothing?' is unanswerable. They think the question stumps us by imposing an impossible explanatory demand, namely, 'Deduce the existence of something without using any existential premises'. The most common use of “why” is as an interrogative adverb, where it introduces a question about reasons or causes. In direct questions, it modifies the verb and helps gather information by asking “for what reason” or “due to what cause.”.