A noun is a naming word. It identifies people, places or things.
1. Common nouns are names given to ordinary objects. They can be identified by ‘a’, ‘an’ or ‘the’. Examples: the shoe, a kitchen, an apple.
2. Proper nouns are names given to people, places, days, months, ideologies, subjects or titles. They always begin with capital letters. Examples: July, China
3. Pronouns are substitutes for nouns, taking the place of nouns that precede or follow them. Examples: I, hers, myself, who.
4. Abstract nouns refer to something that cannot be seen, touched or measured, such as a feeling or emotion. Examples: happiness, romance.