"What are you sewing?"
Translation:Kion vi kudras?
Does Esperanto have a progressive tense? When would I use it if not here?
You can read more about compound tenses in this grammar: http://www.gutenberg.org/files/7787/7787-h/7787-h.htm (use Ctrl+F to search for section "108.")
Thanks for the excellent link! I am still wondering though, when should I use, as in section 110, "mi estas vidanta"? I.e. in what situation would this be preferable to "mi vidas"?
The short answer is that you'll use it when you're describing either a continuous process (which can be readily substituted by the present simple) or a process that was happening at the same time as something else (which is similar to the imperfect tense in Portuguese, Spanish, and French). You can find an explanation here: http://esperanto.50webs.com/EsrGrammar-3_08.html (3.8.7. Complex verbal forms)
The answer about "progressive tense" is no. For the progressive in English, we use a simple tense in Esperanto.
- I am sewing = Mi kudras.
The other answers about "compound tenses" are something different. For what it's worth, I teach the participles as adjectives. There really is no "compound tense" in Esperanto.
You only use "ĉu" when you don't have a interrogative determiner (a what? why? where? how?). As such, it only introduces questions that would be served by English verb auxiliaries alone (Do you? Does he? Will we? Have we? Can I? Should she? Shall they? May we?).
But "Kion vi kudras" isn't necessarily a question, is it like in English where you only need a question mark? ie. "?" Or I guess it would be "kion vi kudri"...
'Kio' = 'what.' Like Luis_Domingos said above, you don't need 'ĉu' when you're using a 'what,' a 'why,' etc. It's like saying: "You sew what" in English, which is grammatically incorrect without the questionmark because 'what' makes it a question.
No, not necessarily. I was thinking of the line "You reap what you sew." which is not a question, even though it does contain the word "what".
That's a different use of the word "what", and it would hardly be considered a question on those terms. If it's not a question, then you could be able to use "ĉu" here anyway because it never means "what" (it would still be kio/kion).
That is true. I'm not 100 percent sure, but I think that 'what' functions as a relative pronoun in your sentence and not as a normal w-question-word.
The way I remember it is that ĉu usually changes a non-question into a question.
Vi kudras = You sew. Ĉu vi kudras? = Do you sew?
Vi kudras kion = What do you sew? What would be the point of adding ĉu here?