I can't say I have pet peeves in english, mainly because I'm not english and I'm not an expert in that language...

but I'm pretty sure I do a lot of those errors. One I can think is with then/than, every time I right it I stop for like 10min asking myself what are the difference and what is the one I should use in that sentence >.< I do almost the same thing with the to/too.

There was a time that i didn't really care if I did some errors, but lately (maybe about 6 months ago) I found out that I was trying my best to right better in english, and I just can't thanks enough the spell checker in firefox now because it sure help me a lot XD

About the mistakes like would of instead of would have, I do a lot of those errors, but not just in english. I have the tendency of typing too fast and some time without even noticing it I type a word that sound the same thing as the word that I was thinking, but the word mean a totally different thing. I do that even in french. I think i do that because I write more like I talk and that's the problem. :\

I'm trying my best to correct those error now, I started to read my post 2 time before posting them now XD which I wasn't doing before...

Along those same lines, I've always had a problem with the phrase "the best of the best." Simply call them the best and be done with it.

My friend says "hurted" a lot on that same note.

There are tons that I dislike, and a few that I'm guilty of that bug the heck out of other people, the most common being "a whole nother" instead of "an whole other" ... but I'm getting better!

My list:
its/it's, their/there/they're, who's/whose, would of, your/you're, then/than, to/too/two, will/well, ones, quiet/quite, wich/which/witch and probably many others that I just can't think of at the moment.

Oh, here's another annoying one: "make due." As in, "You will have to make due with what you have." FYI: IT IS "MAKE DO."

Also, I get pretty irritated with people who say "supposebly." Please, if you say this, know that "supposebly" is not a word. It's "supposedly."

One that bugs me is when people use "per say" instead of "per se".

The little errors do not bother me as much when I am speaking, but flaunted displays of ignorance really make my blood boil. My math teacher (Statistics: never take this class) CONSTANTLY tells us 'you're supposed to times it by two.' My eyes dilate and my hands start shaking every time he repeats this.

I disagree with many semantic inconsistencies, but I do not let it get in the way when I talk. For instance, I silently correct people who use the wrong 'your,' because they are, in fact, pronounced differently.

I remember having a writing class one semester, and most of our time was spent correcting essays. I had so much trouble going through my partner's essays because she had so many grammatical errors, and I couldn't find the main points in the paper. I ran out of time going through the 15+ pages we had to correct during those sessions.

I guess my biggest pet peeve is when people use colloquial language in academic papers, and they're not aware of it. I remember how several people told me I was wrong when I tried to explain why using "ain't" wasn't appropriate during some cases.

I have to go with the very first one pointed out; would of instead would've. I've seen would'f a few times too which makes me cringe...

how about the abundance of folks that use "you're" when they should be using "your" or vice versa

Also mixing up "atypical" with "untypical" seems to be very popular

People who say "anyways" when they mean "anyway".

I cringe when I see 'alot'.... Ewwww.... even writing it wrong gave me the chills....

I really don't like when people mix their future/past/present tenses together. That really gets under my skin. I had to review a doctoral dissertation just lately and the guy's grammar was terrible. It was like, a grammar nightmare. In fact, the entire paper didn't really make sense. It was awful infact! Man, ugh, bad times seriously. OH! And people that over use exclamation points! Don't get me started! Seriously! See how annoying this is! I realize it's not technically grammar but, hell! AND... those "..." they're also annoying when over used.... see... yes it is annoying... sure... I love these little continuation ... deals...

*raises eyebrow*

Yay.