'Good luck!' can mean just what it says -- that the person is wishing you well in your endeavor. However, 'Good luck with that,' especially when said with a sarcastic tone, means that the other person doesn't think you're going to be successful at all.
Example:
-I'm gonna go cram for my Philosophy final tomorrow.
-Yeah, good luck with that!
Really interesting!
ReplyDeleteI would have never thought it was sarcastic! And I used it a couple of times... now I know how to use it properly
Thank you!