Hi I’m a newbie on translations and have…

Hi, I’m a newbie on translations and have just tried my first one on a WP theme that I need in EN+FR+SP+PT. I’ve done the portuguese using Poedit and everything went normal. Then I uploaded the files to the “lang” folder inside the theme but nothing happened. Do I have to “say” to wordpress somewhere about the new language?

Am I on the right place to ask this?

thanks anyway