Why is it that nobody knows the difference between "you" and "you're" ?

they're such common words that you will read them in every day lifeI think much of the problem is that people do very little reading these days, hence they don't catch such mistakes with homonyms. When I was younger, I used to read plenty of fiction books published in the USA. As I got older, I realized that not only had that habit proved extremely entertaining, it was also educational! It broadened my vocabulary and developed my skills in spelling, punctuation, sentence construction and things like when to use which homonym.

hey! don't forget the "there".. LOL! unfortunately, we can't give grammar lessons here. most of the time, it's typographical error. they do know the difference but that's a lot easier to type. that's just my observation.