Nouns

A common noun is a noun that refers to people or things in general.

Ex: boy, country, bridge, city, birth, day, happiness.

A proper noun is a name that identifies a particular person, place, or thing.

Ex: Steven, Africa, London, Monday. 

In written English, proper nouns begin with capital letters.

A concrete noun is a noun which refers to people and to things that exist physically and can be seen, touched, smelled, heard, or tasted. 

Examples include dog, building, coffee, tree, rain, beach, tune.

An abstract noun is a noun which refers to ideas, qualities, and conditions - things that cannot be seen or touched and things which have no physical reality. 

Ex: truth, danger, happiness, time, friendship, humour.

Collective nouns refer to groups of people or things. 

Ex: audience, family, government, team, jury.

Nouns can be either countable or uncountable. 

Countable nouns (or count nouns) are those that refer to something that can be counted.  Ex: Pens

Uncountable nouns (or mass nouns) do not typically refer to things that can be counted and so they do not regularly have a plural form. Ex: Salt, Hair