Example 1:
Person A: "Do you think they'll ever bring back the original Times
Square Toys "
R" Us with the indoor Ferris wheel?"
Person
B: "Yeah, when pigs fly. That space is a Gap now."
Example 2:
Person A: "I'm waiting for the MTA to bring back the V train and paper MetroCards."
Person
B: "Keep waiting. That'll happen when pigs fly."