Why can't animals talk like us?  Some have speculated that a structural distinction exists between other animals and humans that allows us to shape words, but recent research has shown that to be unsubstantiated.  Animals certainly communicate, but they don't create words because the words have no meaning to them.  Of course it's a little more complicated than that,  but that's the gist.  This ScienceABC article explains a few of the important neurological elements essential for the creation of language, with a few teasers about what researchers have considered potential influences on the development of human speech.  A big take-away....look to the brain!