Diagram sentence the speckled blue heeler is an intelligent dog?

In the sentence "The speckled blue heeler is an intelligent dog," the subject is "The speckled blue heeler," which is a noun phrase. The verb is "is," serving as a linking verb. The predicate nominative is "an intelligent dog," which describes the subject. Overall, the structure indicates that the speckled blue heeler belongs to the category of intelligent dogs.