
No, Sheldon,
you can't fix this with gifts.
The Big Bang Theory Season 4, Episode 7

But it can't be The Silver
Shadow-- that's mine.
The Big Bang Theory Season 12, Episode 16

You can't win.
Game of Thrones Season 3, Episode 2

But I can't say it without turning sad.
Game of Thrones Season 4, Episode 5

Can't or must?
The Big Bang Theory Season 11, Episode 8