Question

why animals cannot talk

Answer 1

animals cannot talk because their vocal ability or voice box is not so much advanced like the human beings there are many modules in the voice box of human decibel is very large as compared to other living being

Answer 2

That suggests that the ability to produce them evolved before the orangutan lineage split from the lineage that gave rise to humans. ... The truth seems to be that some animals can mimic the sounds of human speech, but only a tiny minority can talk meaningfully as humans do.