Why do we add S to some words but ES to others? And when a word ends with Y, how do we know whether to change the Y to I before adding the plural suffix? And why on earth does knife become knives? You can unravel these mysteries with six simple rules.
idea for car rides with future children: Road trip clips: One clip for each kid. If they are sweet, clip stays up, if they are not, clip comes down. Everyone with a clip on the visor gets a treat at the next stop.