[Genoa]

It's sort of tricky, and people sometimes blur the distinctions in everyday speech. For example, the Isle of Man is part of the United Kingdom, but technically it's not part of Great Britain, which properly speaking is a geographical term designating the main island. But to make a long story short, there's no excuse for the Manchild calling the whole country "England."

[Genoa]

More specifically about the Isle of Man, and please excuse my pedantry:
It is (locally) self-governing, but its foreign relations and defense are under UK control. (Not that it matters to you and me.)