Gorilla, Volume 8, Number 1, from December, 1984.
One day Koko was having a conversation with Research Assistant Maureen Sheehan.

MS: Where do gorillas go when they die?
Koko: Comfortable hole bye.
MS: When do gorillas die?
K: Trouble, old.
MS: How do gorillas feel when they die, happy, sad, afraid?
K: Sleep.

MS: What’s the difference between you and me?

K: head.

MS: And how are our heads different?

Koko beats on her head with her open hands quite hard, harder than a human would ever do.

MS: What else is different between us?

Koko moves her hand up to her stomach, a gesture resembling BLANKET.

MS: Do you mean something about your stomach?

K: STOMACH GOOD THAT.

MS: Oh, but what were you saying about blanket, different?

Koko moves her hands up and down her torso, then pulls the hair on her belly. Maureen interprets these new gestures as meaning ‘body hair’.

MS: Now can you name something the same?

K: eye.

MS: Yes, that’s right, we both have eyes.

K: love.

Koko has also made verbal ‘jokes’. On 30 October 1982, Barbara Hiller showed Koko a picture of a bird feeding her young.

K: that me [to the adult bird].

B: Is that really you?

K: koko good bird.

B: I thought you were a gorilla.

K: koko bird.

…

B: Can you fly?

K: good. [good can mean yes.]

B: Show me.

K: FAKE BIRD, CLOWN. [Koko laughs.]

B: You’re teasing me. [Koko laughs.]

B: What are you really?

Koko laughs again, and after a minute signs

K: gorilla koko.