A noun is a kind of word (see part of speech) that is usually the name of something such as a person, place, thing, animal, or idea. In English, nouns can be singular or plural.

Nouns often need a word called an article or determiner (like the or that). These words usually do not go with other kinds of words like verbs or adverbs. (For example, people do not also describe nouns). In English, there are more nouns than any other kind of word.

Every language in the world has nouns, but they are not always used in the same ways. They also can have different properties in different languages. In some other languages, nouns do not change for singular and plural, and sometimes there is no word for the.

Examples of nouns: time, people, way, year, government, day, world, life, work, part, number, house, system, company, end, party, information.

The word noun comes from the Latin nomen meaning "name." Words like nouns were described in early days by the Sanskrit grammarian Pāṇini and ancient Greeks like Dionysios Thrax.

In English sentences, nouns can be used as a subject, object, or complement. They often come after prepositions, as the 'object of preposition'.

Nouns can sometimes describe other nouns (such as a soccer ball). When they do this, they are called modifiers or adjuncts.

There are also verb forms that can be used in the same way as nouns (such as 'I like running.')  These are called verbals or verbal nouns, and include participles (which can also be adjectives) and infinitives.

Nouns are classified into common and proper. Pronouns have commonly been considered a different part of speech from nouns, but in the past some grammars have included them as nouns[1] as do many modern linguists.[2]

Proper nouns (also called proper name) are specific names. Examples of proper nouns are: London, John, God, October, Mozart, Saturday, Coke, Mr. Brown, Atlantic Ocean. Proper nouns are individual things with names, not general nouns.

Proper nouns begin with an upper case (capital) letter in English and many other languages that use the Roman alphabet.  (However, in German, all nouns begin with an upper case letter.) The word "I" is really a pronoun, although it is capitalized in English, like a proper noun.

Some common nouns (see below) can also be used as proper nouns. For example, someone might be named 'Tiger Smith' -- even though he is not a tiger or a smith.

Common nouns are general names that are unspecific. Sometimes the same word can be either a common noun or a proper noun, depending on how it is used; for example:

In English and many other languages, nouns have 'number'. But some nouns are only singular (such as furniture, physics) and others are only plural (such as clothes, police). Also, some nouns are countable (for example, one piece, two pieces) but others are uncountable (for example, we do not say one furniture, two furnitures).

The plural form of most nouns is created simply by adding the letter(s) -(e)s.

Despite plural forms being written using the letter(s) -(e)s, the pronunciation of the letter(s) will pronounced as /-s/, /-z/, or /-ız/ depending on which type of phoneme, or unique sound, comes before it. These variations of the plural morpheme are called allomorphs.

Note that some dictionaries list "busses" as an acceptable plural for "bus". Presumably, this is because the plural "buses" looks like it ought to rhyme with the plural of "fuse," which is "fuses." "Buses" is still listed as the preferable plural form. "Busses" is the plural, of course, for "buss," a seldom used word for "kiss."

There are several nouns that have irregular plural forms. Plurals formed in this way are sometimes called mutated (or mutating) plurals.

Many of the above irregular plural forms stem from Old English, which had more complex rules for making plural forms.

And, finally, there are nouns that maintain their Latin or Greek form in the plural. (See media and data and alumni, below.)

Nouns are words for things, and since things can be possessed, nouns can also change to show possession in grammar. In English, we usually add an apostrophe and an s to nouns to make them possessive, or sometimes just an apostrophe when there is already an s at the end, like this:

Most adjectives become nouns by adding the suffix -ness. Example: Take the adjective 'natural', add 'ness' to get 'naturalness', a noun. To see a list of 100 adjectives used in Basic English, click here.

A noun phrase is a phrase where the head word is a noun. In English, the word order of most noun phrases is that determiners, adjectives, and modifying nouns in respective order must appear before the head word, and relative clauses must appear after the head word.[3]