inversion of letters :(

Sometimes when I carelessly or fast I write words like "vent" as "nevt" or "women" as "wonem"
I heard before that this is a language disease, is that so? I do it in my native Spanish too!!! :(

Are you talking about dyslexia?

If so, you probably aren't dyslexic, you would have noticed it before, it's a learning problem. You write words wrongly because, as you said, you write them carelessly and fast. That's it.

I have the same problem, often typing words like "taht", "teh", etc.

It's just because ppl write too fast, I bet that would never happen if I actually had a pen a piece of paper, instead of a keyboard. ^^!