Use proper english.
It really irks me when people don't tow the line when it comes to the English language. It really begs the question of where they went to school when they can't get simple things right. Admittedly, they'll do the lion's share good, but there are always a few things they'll mess up alot. Occasionally, someone will just do stuff wrong as a joke or something but, most grammatical errors are on accident.
There are some who could care less about grammar, and I wish they'd learn, though I'm not going to take the time to educate them on this. I guess this means I just want to have my cake and eat it.
I could of sworn we had books to teach people English. There's one entitled Essentials of Grammar. Read it. You sound like an idiot right now. I realise we're all equal, but apparently I'm more equal than you.