For this small reason, monkeys are unable to speak as we do!
We have always wondered how different we are from our primate ancestors.
We got a smaller, yet better brain, ability to walk upright (though we lost that awesome tail) and most importantly, the ability to speak. This ability has enabled us to evolve in a way that has brought us to where we are.
But a recent study found something interesting about monkeys and their vocal tracts. And the study is about that why monkeys cannot speak like humans. This study was done by a team of international scientists and found that even if 90 percent of DNA of a monkey matches with human being but still they cannot speak because of their cognitive part of brain which does not allow them to speak like humans.