whether

The word “whether” means used to introduce a question or choice between two or more possibilities. In plain terms, introduces a choice between options, similar to "if" but used for alternatives.

“Whether” is pronounced WEH-thuh (/ˈwɛðə(ɹ)/ in IPA).

Here is “whether” used in a sentence: “She couldn't decide whether to take the job or stay where she was.”

“Whether” is a conjunction.

The word “whether” comes from Old English. From Old English hwæther, originally meaning "which of the two" — a comparative form built on the same root as "who".

“Whether” is a very common word in modern English, usually learned at around the B1 level.

They sound identical but are unrelated. Whether is a conjunction introducing a choice or question between possibilities — 'whether to stay or go.' Weather is a noun for the state of the atmosphere: rain, sun, wind or snow. If you can replace the word with 'if,' you want whether; if it involves the sky, you want weather.

Both can introduce an indirect question, and often either works: 'I don't know whether/if she's coming.' Whether is preferred when presenting two clear alternatives, especially with 'or not,' after prepositions, and before 'to' plus a verb — 'whether to leave.' If tends to feel slightly more casual and conversational.

Whether introduces alternatives: 'I can't decide whether to walk or drive.' It often pairs with 'or not' — 'we're going whether or not it rains.' It also follows verbs of doubt or asking, as in 'she wondered whether he had noticed' or 'let me know whether you're free.'

Not always. You need 'or not' when you mean regardless of the alternatives — 'I'm going whether or not you come.' But when whether simply introduces a doubt or indirect question, 'or not' is optional and often dropped: 'I'm not sure whether he agrees' reads perfectly well on its own.