Uncountable nouns, also known as mass nouns, are substances, materials, or concepts that cannot be counted individually. Examples include water, air, time, and happiness. These nouns do not have a plural form and are often treated as singular entities. To quantify uncountable nouns, we use countable units, which are words or phrases that help us measure or describe the amount or extent of the noun. In many cases, we can use our versions of countable units, but in most cases, they are fixed. Collective nouns and countable units for uncountable nouns have overlapped in many places. It is all about how we usually say it. Most importantly, even though we use an indefinite article (a/an) with these nouns, we usually don't count them beyond one because in most cases, they are idiomatic expressions. Counting them with numbers such as three, four, five, etc., will be awkward. "She gave me four bits of information" sounds awkward, whereas "She gave me some information" i