This document discusses countable and uncountable nouns. It provides examples of countable nouns that have both singular and plural forms, such as apple-apples, and uncountable nouns that only have a singular form like money or water. It also discusses using a/an with countable nouns and some/any with countable and uncountable nouns. The document explains how to use how many with countable nouns and how much with uncountable nouns. It includes exercises to practice these concepts.