Common Nouns

These are words that are used to refer to common and non-specific things.

Examples:  girl, boy, camera, computer, keyboard

 Proper Nouns:

These are names of people, places, organisations businesses, schools universities etc.  They are always written with a capital letter, even if they are in the middle of a sentence.

Examples:  London, Paris, Michael, Angela, Mercedes Benz, Honda, Oxfam, King Edward VII, Cambridge University.

Abstract Nouns:

These are words used to name non-physical things. These include feelings, states of mind, concepts etc.

Examples: love, hatered, ambition, cynicism, reluctance, mathematics, sociology

Collective Nouns:

These are words that are used to describe groups of things.

Examples: platoon, class, band, cast

Note:  Some collective nouns can only be used to refer to specific groups.

Examples: herd (of cattle),  flock (of sheep),  gaggle (of geese), caravan (of camels)

IMPORTANT

A singular collective noun refers to one group, but a collective noun in plural form refers to two or more groups of the same thing.
Example: herd / herds

singular:  A herd of cattle is grazing in the field.

plural:  Many herds of cattle can be seen while driving through farm lands.