Countable nouns (also known as count nouns) are nouns that can be considered as individual, separable items, which means that we are able to count them with numbers—we can have one, two, five, 15, 100, and so on. We can also use them with the indefinite articles a and an (which signify a single person or thing) or in their plural forms.
Countable nouns contrast with uncountable nouns (also known as non-count or mass nouns), which cannot be separated and counted as individual units or elements. Uncountable nouns cannot take an indefinite article, nor can they be made plural.
Singular
When a noun is singular and names a person (or, sometimes, a pet) whose gender is known,* then we use the third-person singular he, him, or his (masculine) or she, her, or hers (feminine). For example:
