This document discusses countable and uncountable nouns in English. It explains that countable nouns can be singular or plural, while uncountable nouns cannot be counted or made plural. Some nouns can be used as either countable or uncountable depending on their meaning. Quantifiers like "a/an", "some", "any" are used differently with countable and uncountable nouns. Questions using "how much" and "how many" also depend on this distinction. Examples are provided to illustrate countable vs uncountable usage. Containers and quantities are listed for common uncountable nouns.