"Ĉu jes aŭ ne?"

Translation: Yes or no?

[fxeyub837]

Funny if you could just go 'Ĉu?' ;)

[temrix]

You can just say “Ĉu?” and this means “Really?; Yes?”.

[invernessie]

What is the mechanical purpose of Cu?

[deactivated user]

Its use is similar to the upside-down question mark in Spanish, but spoken, similar to the "ka" at the end of Japanese questions.

[johnclover]

"Yes or no" can be a statement or a question. In english we'd differentiate based on inflection, but inflection for question versus statements vary a lot between languages. So Esperanto makes it really clear for everyone involved with 'Ĉu'.

[temrix]

Actually it is derived from polish “Czy?”.

[ant3hon3y]

Cu recognizes that what you are saying is a question and not a statement or demand

[sebimoe]

Are any of these also correct/usable? "Jes ĉu ne?" / "Ĉu jes, ĉu ne?"

[deactivated user]

Not really. "Jes ĉu ne?" would mean "Yes, isn't it? We might say that in English when someone has said something such as, "It's a lovely day today." However I haven't come across it in Esperanto. "Ĉu jes, ĉu ne?" I would say means "Is it yes? Is it no?"

[Sa967St]

Suppose a factual question has three options: 'yes', 'no', and 'maybe'. If someone is trying to figure out which answer it is and is asking for a hint to eliminate 'maybe', how would they ask "Is it yes or no?"?

[AnnikaQED]

Since "cxu" is supposed to introduce a question with a "yes/no" answer, I assume this is short for "Cxu jes au cxu ne"

[deactivated user]

"Ĉu" isn't only used for questions where the answer is yes or no. With "aŭ", for instance, it can introduce a question giving two alternatives. For example, "Ĉu la viro estas grava aŭ malgrava?" or that most famous Shakespeare question, "Ĉu esti aŭ ne esti?" "Ĉu" is also used to translate the English words whether and if, in sentences such as, "I wonder if it will rain tomorrow" and "He needs to know whether the story is true."