Knock, knock...
Who’s there?
The electrician...
The electrician who?
The electrician who you called earlier, I understand you’ve been having some problems with your door bell?
Knock, knock...
Who’s there?
Terrible English Teacher...
Terrible English Teacher who?
It’s Whom.
Knock Knock...
Whose there?
Burglar...
Burglar who?
Come on now, you know a burglar wouldn't knock!
Knock Knock...
Who's there?
Owls say...
Owls say who?
Yes, yes they do.