Student or Learner
Would like to know if slim chance (less likely to succeed) has an opposite meaning to fat chance (more likely to succeed?
Anthony the learner
No they mean the same except that "fat chance" is sarcastic.
There is a slim chance he will pass the exam.
Peter thinks he'll pass the exam? Ha! Fat chance!
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.