A favourite I collected from a boss I had for a few years that I'm sure everyone has either heard or uttered:
For all intensive purposes
Note: The correct phrase is "for all intents and purposes".
Another of my all time favourites is when the literal meaning is precisely the opposite of the intent, eg.
I could care less about X
I literally mean: I could care less about the welfare of my children. But then I don't think I actually could care less, as in I can't but care, however in that case then this would also be true:
I couldn't care less about the welfare of my children (I just couldn't!)
A favourite I collected from a boss I had for a few years that I'm sure everyone has either heard or uttered:
For all intensive purposes
Note: The correct phrase is "for all intents and purposes".
Another of my all time favourites is when the literal meaning is precisely the opposite of the intent, eg.
I could care less about X
I literally mean: I could care less about the welfare of my children. But then I don't think I actually could care less, as in I can't but care, however in that case then this would also be true:
I couldn't care less about the welfare of my children (I just couldn't!)
Interesting conundrum.