Recently this has really started to get at me (mainly due to people on the internet making these mistakes without anyone correcting them), so I'll create a thread on it...
I'm quite picky when it comes to grammar and stuff like that, so don't take this personally if it applies to you.
Common Mistake #1: 'I could care less.'
Description: Please just think about the above statement and then consider how contrary it is to its intended meaning. When you say, 'I could care less,' you mean that you don't care at all. Therefore, you could
n't care less. If you 'could care less' then you obviously care about whatever it is that wants caring about to some degree.
The correct phrase is: 'I couldn't care less.'
Common Mistake #2: i) 'This game is really addicting.' ii) 'I have an addictive personality.'
Description: i) It's just poor English, like it's been simplified for foreigners or kids for the sake of regularity. Unfortunately, the introduction of this word means that the meaning of 'addictive' also becomes confused.
The correct phrase is: 'This game is really addictive.'
ii) 'I have an addictive personality,' when thought about, means 'People find me attractive because of my personality.'

After all, if your personality is addictive, then it means that people can't get enough of it...
The correct phrase is: 'I am an obsessive.' Or: 'I have a compulsive obsessive personality.'
I'm not sure about that last one...
I may update this at some point, with 'There, their and they're,' and other mistakes, but I feel I've made my point for now.
