Classical Conversations' Essentials program teaches us that there are nine different usages (jobs) for a noun (subject, direct object, predicate nominative, etc). However, my goal over the past few weeks, and throughout the summer months, is to have my children master the main five -- Subject, Possessive, Indirect Object, Direct Object, Object of the Preposition. Why? Because one day (relatively soon for my son) my children will take Latin. In case you are unfamiliar, Latin nouns decline (their endings change) based on their job (or function) in a sentence.
We have been filling our mornings with some learning activities to aid us in our challenge. Of course the simplest way has been reading....and writing....and rewriting sentences. Repetition. We will take a sentence and begin by highlighting all the nouns listed. Then we will ask ourselves a series of questions to help us identify which function each noun has. For my children, some are easier to spot than others (a possessive or an object of a preposition). Once they begin to understand that specific function, I ask them to begin making up their own sentences. For example. "Give me a sentence with a possessive subject and a prepositional phrase." Mom's keys are in her purse.
Direct and indirect objects have been a little more fun because we can include our study of action verbs and play a few more games. Mad Libs and I Spy are two. I spy the (dog, cat, pinwheel, butterfly, etc). All those nouns, in that sentence, are direct objects. In fact, they'll even get creative with 'I spy the neighbor's cat' in order to have a possessive direct object.