Common n. are names that can be applied to any individual of a class of persons or things, collections of similar individuals or things regarded as a single unit, abstract notions, materials.
Class nouns denote persons or things belonging to a class.
Collective n. denote a number or collection of similar individuals or things as a single unit. They fall under the following groups:
-nouns which are singular and denoting a number of things collected together and regarded as a single object.
- nouns which are singular in form though plural in meaning: police, cattle, people, gentry. They’re usually called nouns of multitude.
-noun that may be both singular and plural