(7) Her dog chases rabbits.
For example, her dog and rabbits in (7) are both noun phrases, but they have different functions in the sentence. Although we haven't yet specified these functional roles, we can already see that each noun phrase has a different role in the sentence. The dog is doing the chasing, and the rabbits are being chased. The role of her dog is probably already familiar to you: it serves as the subject of this sentence. Rabbits plays a role known as the direct object, which we will study in the next chapter.