"Does he come from South America?"
Translation:Ĉu li venas el Sud-Ameriko?
I even have my doubts, if the hyphen should be used at all ! It is useless in Esperanto, I never used it.
Found in Plena Analiza Gramatiko, paĝo 32 ( https://cindymckee.com/librejo/Plena_Analiza_Gramatiko_%28K._Kalocsay,_G._Waringhien%29.pdf ) some rules to use hyphen... check it.
I do not see any major problem in saying "Ĉu li venas el Sud-Ameriko?", but I also think that the hyphen is unnecessary.
I found that B. Kolker: Lingva Ret-Gazeto - LRG-1, [1996?] said people may use hyphen to indicate exactly which are the words in a word construction in Esperanto.
I still think its unnecessary, and odd.
There is a difference between suda Ameriko and Sud-Ameriko. Suda is an adjective, i.e. southern, while Sud- is the first part of a compound. It's like the difference between southern America and South America. In compound words the hyphen is optional, but can be used to help reading. So, for instance, you could write litoĉambro (bedroom), or lito-ĉambro. What you can't do is write lito ĉambro, i.e. put one noun after another without connecting them. So you could write Sud-Ameriko or Sudameriko. I suppose you could also write SudAmeriko, but it looks rather odd without the hyphen.
"De" means "from", and "el" means "out of". You could use both, but there's a slightly different shade of meaning. "De Sud-Ameriko" simply means that he has come from South America. "El Sud-Ameriko" means that he was somewhere in South America and has come from that point inside South America. In practice you can use either in that sentence.