Monkeys are related to fish because if need be they can breathe underwater.

Monkeys are primates, while fish are aquatic vertebrates - they're completely different classes of animals. Monkeys breathe air using lungs and cannot breathe underwater. The evolutionary relationship is that all vertebrates share a common ancestor from hundreds of millions of years ago, but this doesn't mean monkeys are 'related to fish' in any meaningful way for underwater breathing. The statement is false.