Context clues

Kid 1: I saved these animals from a thorn bush!
Me: They must be thrilled.
Kid 1: No, they're nice animals.

Still Wilbur

Kid 2: You're the daddy monster... And you're the mama monster... And I'm the baby monster!
Kid 1: And I'm the family pig!

Jocularity

Kid 1: Mom, wanna hear a joke? What if... someone put their face first in YOGURT?

She's got the "funny" concept but not the part about the punch line.

Junk food you will be

Kid 2 is fond of a tiny green action figure: "'Smy bes' frien' Soda. He got a LifeSaver."

Fellow-feeling

Kid 1 mopes into the next room.

Kid 1: I got in trouble with Mom.
Dad: What did you do?
Kid 1: I don't want to talk about it, I just want some sympathy.

Life imitates art

Kid 2: Tomahto, Mom, want a tomahto.
Kid 1: I want tomatoes, too, Mom! Tow MAY tow!
Kid 2: Tomayto?! NO! Tow MAH tow.
Kid 1: Tomayto.
Kid 2: Tomahto.

Affectionate

The small one is our cuddler, and not afraid to ask. She corners the big one in the hallway.

"I baby thithter. Baby thithter. A hug. A kith. Nithe to mee tyou. [Shakes hands with sister.] Nithe to mee tyou, [Sister]. Hold me."

Litany

Praying for lunch, 20 month old version:

"God...
Jesus...
Cake.
An' juice.
An' cake.
Amen.
Clap meh hands!"

Melting

Big sis: I'm sorry, Care Bear.
Little sis: Hug?
Big sis: She forgives me!
Little sis: Hug!

Victualed

Kid 2: Summer soup! Summer soup!

I looked up to see her folded in half with her feet and forehead on the floor.

Me: Somersault?
Kid 2: Oh, summer SALT. Help somersault!