There are no such things as "stupid" questions. However if you think your question is a bit stupid, then this is the right place for you to post it. Please stick to easy to-the-point questions that you feel people can answer fast. For long and complicated questions prefer the other forums within the support section. Before you post please read how to get help
If you make SMPlayer full screen do you see an icon that looks like a screw driver? If you do click on that if not press Ctrl P then interface should be the 5th option down (which you can see in my screen shot) so click on the option that's in the same place. Then click the on the menu that lines up with the Language: from my screen shot and select English.
Well, it does change the language (yay) but rather than actually changing languages, it takes the characters it would normally have and replaces it with Greek characters again. No matter which language I choose (Even Right to Left ones!)
SMPlayer isn't unusable right now, it's just funny Any one else?