All the evidence is that there's a lot less of theirs to learn, & they don't have much to say.
They can learn to understand quite a lot of words of ours, but have failed to learn to communicate in any of our languages beyond a very basic level, despite great efforts to teach them.
Dozens of signs & gestures used by great apes for communication have been identified. Note that: dozens. Copying those isn't particularly difficult, as far as I can discover, but researchers don't find it very interesting, not like trying to teach 'em something more complicated.
With intensive & lengthy teaching, a few have learned to use a few hundred signs - but none of them have learned to use them as humans do, & they learn them very slowly indeed by human standards.