My Five Biggest Pet Peeves of Written English Language Use

In no particular order:

1. Using "your" instead of "you're"
2. Misuse of there/they're/their
3. Using apostrophe S ('s) on plurals (e.g. taco's should be tacos, DVD's should be DVDs, 1950's should be 1950s)
4. Writing "should of" instead of "should have" (it's based on hearing "should've" and then misinterpreting the phonemes for the words)
5. Writing a comma where there should not be a comma (e.g. "Writing a comma, where there should not be a comma.")

Bonus pet peeve: When people give you a list of there item's, and then they list bonus item's when they could of just extended the list. Seriously, your not stupid, so why list a bonus, when you don't need to.