What are countable and uncountable nouns?

Countable nouns refer to things that can be counted (e.g., “book”). They can be pluralized (e.g., “books”) or preceded by an indefinite article (e.g., “a book”) or a number (e.g., “three books”).

Uncountable nouns (also known as mass nouns) refer to anything that cannot be counted and is always treated as a mass (e.g., “information,” “research,” “advice”). They cannot be pluralized and are never preceded by an indefinite article or a number, though they can be preceded by an indefinite quantifier (e.g., “some,” “any,” “little”) or the definite article, “the.”

QuillBot’s free Grammar Checker can help you avoid mistakes with count and noncount nouns.