Now the problem is, not all of us speak this language. I personally don't, I even have trouble speaking English, my native language. This is where you can come in.
There's a few ways to participate in translating addons. For example, one of my addons called Ackis Recipe List is hosted on WowAce (http://www.wowace.com/addons/arl/). You can navigate there, and find the localization tab, and from there you can see Brazilian Portuguese as an option. From that point, there's a list of English phrases which need translating. A direct link for you to look at is this: http://www.wowace.com/addons/arl/localization/ptBR/
If addons aren't hosted on WowAce/CurseForge you can still help out. Find out if the addon supports localization (e.g. it's already translated into other languages) and if so provide a translation set for the author.
Thank you all for reading!