Meaning: This sentence describes a large dog that is sleeping in a shaded area.
Choice of Words: "Big" is an adjective used to describe the size of the dog. "Dog" is a noun that refers to a domesticated carnivorous mammal. "Sleeps" is a verb that describes the state of being asleep. "In" is a preposition that indicates a location or position. "Shade" is a noun that refers to a partially shaded area.