My mom is more of a grammar Nazi then I am. Or is it than?
Than. Then is time/progression, than is comparative.
People will ask me if I can do something and I will reply that I CAN.
I hate when people do that. Hate. I don't care that it is more grammatically correct or anything, you know what I am asking of you, if I have to change what I am saying just to please you, I will go do stuff myself.
Same with the can/may thing, it's just... Frustrating and humiliating to be put through those trials just because of words.
That said, obviously I am not classified as a grammar Nazi. I don't care for the way some people write either, either with the chat speak or confusing homonyms, it may be annoying to look at, but I do find it petty to go correct them. More so, if it occurs in a discussion or during something serious.
In discussions it just seems like you are throwing ad hominem at the opponent instead of debating them, and if it's a serious situation, well... Imagine this:
"Oh God, my parents were in an accident! I have to go see them, I hope there alright!"
"*they are"
I am pretty sure that is the first example in the book of 'How to be a ****** on the internet'.
Another fine reason is that people might not catch the mistakes themselves, and are thus humiliated once again, because some people are idiots that wants to point out small mistakes.
Besides, consider the one day where you are having a brain fart and mess this up.
I tend to refer to theOatmeal's comics on the matter, if I need to refer to anything. I often have to, as I mess up pretty badly sometimes because English is a hard language and my sentences are long and complex.
I also abuse commas because the English comma rule sucks butt.