什么是I-spy-with-my-little-eye这种游戏？

I spy with my little eye is a game loved by American children! But what exactly is it? It's simply a guessing game, but often played during the lulls of activities like driving. A person secretly picks an item and starts off with "This thing begins with..." (e.g., this object starts with W), then everyone tries to guess until they get it right, before switching roles.