"The teacher is from Dresden."
Translation:Der Lehrer kommt aus Dresden.
Both "Der Lehrer ist aus Dresden" and "Der Lehrer kommt aus Dresden" are fine. Personally, I prefer the latter. "Der Lehrer ist von Dresden" is wrong in Standard German. It might be used in some regional dialects, though. Germandy, if you don't mind me asking, what part of Germany are you from?
Oh. I wasn't certain about the "ist aus.." because I thought it's one of the things people say although it's not correct. Apparently it's not, but the "ist von.." is and I wasn't aware. Thanks for letting me know! ;) It's possible that it's a regional mistake - I am from NRW around Cologne / Aachen (but study in Berlin).
In general I prefer "Der Lehrer kommt aus Dresden" too, though.