It seems that people who make comments on blogs and other social sites make a few grammar errors.
I wonder if there have been any studies of what fraction of blog comments have grammatical errors. People making comments don’t want to spend a lot of time proof reading what they have written, especially when many blogs require you to sign up in order to post a comment.
I have seen the following mistake on a few blog comments, but not in a blog post. People say “your on a roll”, where they mean “you’re on a roll”. I guess it is an easy enough error to make, when english also contains the phrase, “this is your”, as in “this is your donut”.
“You’re” is meant to be an abbreviation of “you are”, which is distinctive from “your” which means that the person you are talking to has something.