Teaching Koko sign language eventually became a lifelong hobby and caregiving relationship to Dr. Patterson. In the early stages of teaching, Koko learned one new sign every month. But soon enough, Koko was combining signs to convey more complex concepts, pairing up signs for "more" and "eat," for example, to ask for more food.
Koko the gorilla is probably the best-spoken animal in the world. After all, she's had more than 40 years of practice. She began in 1972, when animal psychologist Francine Patterson taught her American Sign Language as a part of her PhD project to see if humans and gorillas could communicate.