This is due to thousands of years of divergent evolution! We have evolved to speak different languages and the reason we can do this because we have different tongues! The tongue and lip movement is critical in forming various sounds and the orang-utans don’t have that dexterity! Try to not move your tongue or limps when you say words! It is very hard and sounds nothing like the word you were trying to say! This lead to the evolution of humans that could move their tongue and lips more as they could communicate better and thus it has lead to the modern human! 🙂
It is fascinating though how much DNA we can share and yet how different we actually are! 😀 We share quite a lot of DNA with a banana too! Haha!
Hope that answers your question! If not… ask me more! And please vote for me! I wan’t to help more young scientists with the prize money 🙂