No, that's not true. They can't talk because they don't have the physical structures to enable them to talk... just like you can't hang by your
tail because you don't have a tail.
There's good explainations, but they're long and involve linguistics and neurophysiology and physiology. Linguistic research (Choamsky and others)
suggests that the base language of non-humans is fairly small and the number of ideas they convey to each other is small.
Recent genetic studies show that humans diverged from the hominid lineage with a genetic variation that allowed them to progress more quickly in the
areas of hearing and (oddly enough) smell. Chimps simply can't hear the phonemes (which is another reason they don't have a sophisticated
language.)
There's a bunch more to it than that, but you probably don't need several courses worth of animal psychology and anthropology and linguistics dumped
on you.
dsc.discovery.com...