Nouns are usually things, people, names or places, but do not have to be tangible, and can be abstract in nature (such as a concept). Examples:
sea (a common noun), brother (a common noun), Sarah (a proper noun), New York (a proper noun), honesty (a common noun)
Proper nouns (as opposed to common nouns) are a specific name, so are always capitalised.
Because nouns have so many types, they constitute a large part of the English language. And because the subject of a sentence is always a noun, and a sentence always needs a subject, a noun is found in every English sentence.
Types of common nouns
Generally speaking, common nouns can be sub-divided into the following categories:
1. Concrete nouns – nouns that can be seen, heard or visualised. Examples:
I saw a swan. She was listening to a song.
2. Abstract nouns – usually ideas, concepts or processes that cannot be visualised. Examples:
Honesty is a virtue. The benefits of capitalism are clear.
3. Collective nouns – nouns that express a group of something. Examples:
There are 12 people in my team. Elephants live in a herd.
4. Singular nouns. Examples:
A man. A dog. An idea.
5. Plural nouns. Examples:
Men, dogs, Ideas.
Note that some words are already plural (men in the above case), so the original singular noun is not used with an s (so never mens).
6. Uncountable nouns. Examples:
Water, love, chocolate.
Note that uncountable nouns can be made countable by adding another noun. Example:
A glass of water. An act of love. A bar of chocolate.
Nouns as subjects, objects and complements
Subjects, objects and complements to these within clauses and sentences are always nouns. If an action is being used as a subject of a sentence, then that action is converted into a gerund (-ing form of the verb). Examples:
Martin is a fine dancer. (Martin is the subject and dancer is the subject complement.)
Fishing is a fun activity. (Fishing is the subject, and because it is an action, it must be a gerund.)
Tina has two brothers. (Tina is the subject and brothers are the object.)
Jan took the plane to Madrid. (Jan is the subject, plane is the object and Madrid is the indirect object.)
Appositive nouns are nouns that immediately proceed another noun to define it more clearly. Example:
My dog, Bruno, is a Labrador.
Compound nouns are nouns that are comprised of two nouns, with the first noun further defining the noun. Example:
Seatbelt, powerhose, hairbrush
Pronouns and possessives
Often when a noun is obvious it is replaced by a pronoun. Pronouns can be the subject, object, possessive or even reflexive. Furthermore, both common and proper nouns can be made possessive by adding ‘s. Examples:
I don’t enjoy Latin. It is a difficult subject – subject pronoun
Tony is a good guy, I like him – object pronoun
It’s not your pen, it’s my pen (or mine) – possessive pronoun
Paul and Trevor are always hurting themselves – reflexive pronoun
That is Sheila’s bicycle – possessive noun.