Conversation in the car...

A conversation in the car after we had to pull over on Colorado Blvd. for an ambulance to go by, sirens and lights blaring:

Sami: That's a fire truck, Mom.
Me: Actually, no honey. It is like a fire truck, but it is called an ambulance.
Sami: No. That's a fire truck.
Me: They're very similar. But a fire truck goes to fires, and an ambulance helps people who are hurt. That was an ambulance.
Sami: It is a fire truck.
Me: They look alike, don't they? And they both have sirens and lights. But an ambulance is a little smaller than a fire truck and does something different. So that one was an ambulance.
Sami: But it is a fire truck.
Me: No, really. It was an ambulance.
Sami: Oh call it whatever you want.