Deaf people can converse in sign language.

Deaf-mute people talk using sign language.

Deaf people can talk in sign language.

Dr. Patterson communicated with a gorilla using sign language.

Dr. Patterson: She made the sign for cat.

Dr. Patterson: Not at all! Koko has taught us that gorillas are intelligent enough to learn sign language.

Koko knows and uses more than 500 words in sign language, the language of deaf people.

In 1972, Dr. Francine Patterson started to teach sign language to Koko.

Tom wanted to become a sign language interpreter.

Tom learned sign language.

Are you familiar with sign language?

You don't need to speak to Tom in sign language, because he can read lips really well.

You don't need to speak to Tom in sign language, because he can read lips really well.

Tom wanted to become a sign language interpreter.

We talked in sign language.