Noun

Nouns are often the physical things that you can see, feel, hear, smell, and touch. Nouns are also non-physical things, like thoughts, love, and ideas.

A "Noun" is a type of word. (These types of words are called word classes.)

Characteristics
"Noun" is a universal word class, because all languages have nouns and verbs. Nouns often have the following characteristics:
 * Nouns are often countable. e.g. There are 3 chairs.
 * Nouns are often concrete. e.g. Mary, the chair, the sun.
 * Nouns are described by the word class adjectives.
 * Nouns are an " open class " because n ew words are being added to the list of nouns all the time. (e.g. The word "muggle" is a new word from the Harry Potter books. It did not exist 20 years ago.)

Is it a Noun?
Nouns are usually people, places, or things. You can often use simple English question words (who, where, what) to find out the noun (or noun phrase) of a sentence.

Here are some examples: (Note: I'm not sure how useful these tests would be to non-English speakers.)

Grammar
When we do a grammatical analysis, we usually use the abbreviation "N" for nouns.

Nouns have the following grammatical aspects:
 * CASE
 * DEFINITENESS
 * NUMBER

Types
There are 3 types of nouns: