Where do you come from in German duolingo

"Woher kommt Karl?" Where is Karl coming from? "Wohin geht Karl?" Where is Karl going (to)? Woher kommst du?

"Where do you come from" is "woher kommst du," but "do you come from" is "kommst du aus" because "woher" is a pronominal adverb that combines "where" and "from" (essentially the German equivalent to "whence"). If you're not including the "where," you have to include the "from."

"Where do you come from?" in German Woher kommen Sie?

"Woher kommst du?" ("Where do you come from?")