What would the world be like if animals could talk?

All the advanced animals in the world have their own languages, but we just can't understand them. I guess what you want to say is: What would the world be like if other animals could speak human languages? The answer is: it will still be like this. Parrots can speak human language. American parrots even know what they are talking about. Its intelligence is equivalent to that of an 8-year-old human. So your real question should be: What would the world be like if other animals were as smart as humans and could speak human languages? That would be fun. It is good material for science fiction.