Oh yeah, sometimes I'll wear my ASL shirts around the house. Some of them have pictures of tanks on them. John saw one and asked what is was, and I said it's a tank, and he said "water!" Ha, clever boy, and not too far from the origin of the word. When the British were first developing the tank for use as a weapon in WWI, workers were told they were building water tanks, and the name stuck.

And Hanna is just as clever. She asked what it was once, and I said a tank, and she started saying "choo-choo!" And I realized oh, she's thinking of Thomas the Tank Engine!!