edgood  —  Grammar Tips
A noun is a person, place, thing, or idea or emotional state. Nouns are characterized by their ability to form plurals and to take possessive endings. The noun serves a variety of roles in our sentences.

Consider the following sentence. In it you'll find all 10 functions the noun performs in the English language:
The professor, John Smith, is the noun expert, so yesterday he gave the class his views on the importance of learning to write papers clearly, his students feverishly taking notes on all he said.
The 10 functions are as follows:

1. subject (professor) 2. predicate noun (expert) 3. direct object (views) 4. object of verbal phrase (to write papers and taking notes) 5. indirect object (class) 6. object of a preposition (importance) 7. noun appositive (John Smith) 8. noun modifier (noun expert) 9. noun adverb (yesterday) 10. noun absolute (his students feverishly taking notes on all he said)