Nouns are any naming words for people, animals, places, things, ideas, and qualities. In fact, they name everything around us including those that are invisible (wind, gas, vapour).
A noun in a sentence can be recognized by the word called determiner or an adjective that comes before it. The determiner (articles are also determiners) can be one of the following with the nouns are in bold:
Articles: the, a, an (the duck, a hen, an egg)
Determiner: my, some, this (my wallet, some money, this coin)
(1) It acts as the subject of a sentence. The subject is a noun that performs the action of the verb in the sentence and is easily recognized as it usually comes at the beginning of a sentence and followed by a verb.
The man stepped on my toes.
(The subject is the man (a noun) and it comes before the verb stepped.
(2) It acts as an object in a sentence. The object is a noun which is acted upon by the subject.
Tom bit his nail.
(The object is nail (a noun) that typically comes after the verb.)
(3) It acts as a subject complement that follows a linking verb (am, is, was, are, were, has, being, been, seem, become) and modifies the subject.
My uncle is a wine taster.
(The subject complement is a wine taster.)
Different types of nouns
There are many different types of nouns. The most common ones are common nouns, proper nouns, concrete nouns, and abstract nouns. Many nouns belong to more than one of these categories. For example, the noun elephant is a common noun, a concrete noun as well as a countable noun.