I already told Traycer, but purposefully instead of purposely drives me nuts. And something that has been creeping in a lot recently is something like 'you coat' instead of 'your'...

I shrug philosophically over 'I seen it' (and 'I have went') - I've been hearing those all my life and I suspect they've been around since grammar began.

Of the ones here, lay down (and all its cousins) is my biggest hate. I can understand where confusion can arise, but...