Deixis

Set-up 1: The Oyster has been a little gorilla for much of the afternoon. Mama and K (his grandmother) are big gorillas. Great satisfaction is had from making statements such as "big gorilla putting little gorilla's wellies on", "big gorilla using a rake and little gorilla using a spade" (yes, we're still up to our ears in the garden project).

Set-up 2: The Oyster is beginning to use possessive adjectives, but he hasn't figured out deixis yet, so he tends to use "my" to refer to things that belong to the person he's talking to ("put it on my plate - no, MY plate" [points at Mama's plate]).

Oyster: Unny put the stone in my bucket.
Mama: Yes, that's right, you put it in your bucket.
Oyster: No, my bucket!
Mama: Yes, but the thing is, if you say "my bucket", I say "your bucket" - because thaaaaat's deixis, boy!
Oyster: Daa-day-igah-g'illa!
Mama: My apologies. You're right, of course. That's deixis, gorilla.

You've got to get these things right, you know.