Samuel Pepys (1633–1703), famous for his seventeenth-century diary, wrote about what he called a “baboone” and suggested that it might be taught to speak or make signs. And although it was long known that primates use a number of methods of communication in the wild, early attempts (1900–1930s) to teach primates simple words were failures. A 1925 scientific article suggested sign language as an alternative to verbal language in communicating with primates. In the 1960s, researchers tried to teach chimps and gorillas a modified form of sign language. It began with Washoe the chimpanzee, followed by the gorillas Michael (now dead) and Koko. Washoe learned a little over one hundred signs, but Koko has a working vocabulary of over 1,000 signs and understands about 2,000 words of spoken English.