One theory is that humans’ spoken language evolved from gestures. In fact, babies are able to learn sign language before they’re able to talk, so it’s no wonder a language was created based on series of gestures. Predominantly used by people who are unable to communicate verbally or have hearing impairments and their loved ones, sign language uses complex hand gestures and postures to communicate. It’s completely different from country to country in terms of vocabulary, grammar, “pronunciation” and more. American Sign Language is made up of thousands of nuanced signs for words and ideas as well as an alphabet for fingerspelling.