Compound nouns are usually made up of two different words: nouns, verbs, adverbs, or adjectives. Forming the plural of these nouns does not follow a set of precise rules, but there are some general guidelines you can use. Generally speaking, the plural form of a compound noun is made by pluralizing one or both of the words that comprise it.
The following guidelines will focus on the category of compound nouns comprised of nouns + nouns.
The following guidelines will focus on the category of compound nouns comprised of nouns + nouns.