Mostly mine are things said incorrectly such as "valentimes day", "I seen him", "she look good", etc
Also I hate when people say "whenever I was.." Instead of "when I was..". Whenever is for general things, such as "whenever I go get the mail, the neighbors dog barks at me", when is for specific, like "when I was five I got a dog" but I noticed people say "whenever I was five, I got a dog" and it just sounds so wrong that it irks me.