Yes it is.
You can ask and respond questions in any of this three languages: English, Spanish and Portuguese.
Keep in mind that StackOverflow has a different community prefix for each language on their website:
es.stackoverflow.com - for Spanish.
pt.stackoverflow.com - for Portuguese.
stackoverflow.com - for English.
1) Enter StackExchange filters webpage following this link.
2) Create a new filter for the tag you want Stackoverflow to keep you informed.
3) Finally, you will have to confirm your email address.
1) First, you need to know your account id on StackExchange.
Follow this link and go to your profile page.
Then, copy the number that appears in the URL at the top of the screen.
2) Edit your GXAccount adding the Stackoverflow account id.
How do I search for an issue before posting a new question on Stackoverflow?
Follow this guide.
Follow this guide.
Follow this guide.