Language focus: asking "Who are you"? and exploring Halloween costumes

Lyrics:

Knock knock. Trick or treat?
Who are you?
I'm a ghost. I'm a little ghost.
Knock knock. Trick or treat?
Who are you?
I'm a ghost. I'm a little ghost.

Knock knock. Trick or treat?
Who are you?
I'm a cowboy. I'm a little cowboy.
Knock knock. Trick or treat?
Who are you?
I'm a cowboy. I'm a little cowboy.

Knock knock. Trick or treat?
Who are you?
I'm a witch. I'm a little witch.
Knock knock. Trick or treat?
Who are you?
I'm a witch. I'm a little witch.

Knock knock. Trick or treat?
Who are you?
I'm a monster. I'm a little monster.
Knock knock. Trick or treat?
Who are you?
I'm a monster. I'm a little monster.

Knock knock. Trick or treat?
Who are you?
I'm a ballerina. A little ballerina.
Knock knock. Trick or treat?
Who are you?
I'm a ballerina. A little ballerina.

Knock knock. Trick or treat?
Who are you?
I'm a pirate. I'm a little pirate.
Knock knock. Trick or treat?
Who are you?
I'm a pirate. I'm a little pirate.

Knock knock. Trick or treat?
Happy Halloween. Happy Halloween.
Knock knock. Trick or treat?
Happy Halloween. Happy Halloween.