Do you find a Chinese-only speaker talk to Polish-only speaker on a daily basis? No, you don't.
The problem we can't communicate with dolphins is beause first: we don't know their language, second: their language is much more advanced phonetically than our languages, third: dolphins are incapable of pronouncing our sounds just like we are incapable of pronouncing theirs, they have no hands so they can't be taught like monkeys.
Theory of evolution makes sense to people who understand it. Look at Heidi, several years and she still doesn't grasp this, you're probably the same. All is left is to pity you both.