Anchor: Couldn't it have been about half-past three?"
Entailed: Is it possible, that it was about half-past three?
Contradiction: It couldn't have possibly been half-past three, could it?
Contradiction: Donald Trump erects exciting, bold, and attention-grabbing buildings.
Contradiction: There are many people on the street.
Contradiction: The man is clean shaven.
Contradiction: The woman and the dog are outside.