Grammar Terms: Noun

How rikaichan (a Firefox pop-up dictionary add-on) marks a noun.

n = noun (It doesn't differentiate between "common nouns" and "proper nouns" at this time.)

 What is a "noun"?

A noun names: a person, a place, a thing, or an idea.

Nouns are usually used as the subject or object in a sentence.

 A "common noun" vs. a "proper noun"

A common noun is a vague name for something.

A proper noun is the noun's PROPER, correct name. A specific person, place, or thing. Written with a capital letter.

 Common noun examples

Person: mailman
Place: hospital
Thing: refrigerator
Idea: sorrow

 Proper noun examples

Person: George Washington
Place: Central Park
Thing: Pepsi

 Japanese nouns

Japanese nouns don't really specify number (no "a dog," "the dog," "the dogs"-- just "dog").

 About colors as nouns

It seems a little confusing in English, but it's important to note the difference between aka (noun) vs. akai (i-adjective) in Japanese.

赤がきらいです。
aka ga kirai desu.
I dislike red (<--noun).

赤いペンです。
akai pen desu.
(It) is a red (<--adjective) pen.

 Credit

1. Dictionary.com
2. http://www.uottawa.ca/academic/arts/writcent/hypergrammar/nouns.html
3. Language Arts Grade 6