What makes a word noun?

A word is considered a noun if it fulfills the following criteria:

1. Represents a Person, Place, Thing, or Idea:

* Person: John, teacher, student

* Place: school, city, mountain

* Thing: book, car, computer

* Idea: freedom, happiness, love

2. Functions as the Subject or Object of a Sentence:

* Subject: *The dog* barked.

* Object: She read *the book*.

3. Can be Modified by Adjectives:

* *Beautiful* flower

* *Fast* car

4. Can be Pluralized:

* Cat - Cats

* Tree - Trees

5. Can be Used with Articles (a, an, the):

* *A* cat

* *The* car

6. Can be the Object of a Preposition:

* Under *the table*

* In *the car*

Note: Some words can function as different parts of speech depending on their context. For example, "run" can be a verb ("I run every day") or a noun ("Take a run around the block").

Let me know if you'd like examples or have more questions about nouns!