Just because you speak a language doesn’t mean you know how to write and just because a lot of people in your community spell it that way doesn’t mean it’s correct.
I’m not calling you illiterate, but illiteracy means you can’t read and write, it doesn’t mean you can’t speak. A lot of people know how something sounds, but they don’t know how to read and write it. You can’t use “Spanish is my first language” as a reason for saying that you’re correct. When I was in school, there were quite a few native speakers of Spanish who could pass the speaking part of class, but they got points off for writing. If they were in their home country, they’d be illiterate.