A noun is a person, place, thing, or idea. For example, a ‘bike’ is a noun because it is a thing. A ‘boy’ is a noun because it is a person. A ‘house’ or a ‘park’ are nouns because they are places. The noun ‘freedom’ is an idea. These are all examples of common nouns because they only consist of one word and are not capitalized. There are also nouns called proper nouns. They are also a person, place, thing, or idea, but proper nouns can consist of more than one word, like Mrs. Carol. They are also always capitalized.