How do you go from a singular noun to a plural noun?

Answer 1

A singular noun is a word for one person, place, or thing. A plural noun is a word for two or more people, places, or things.

Some nouns form a plural by adding the S or ES to the singular noun (frog, frogs, church, churches). These are called regular plural nouns.

Some words use the same word for both singular and plural (deer, aircraft), and some words change the form of the noun to form the plural (child-children, man-men, goose-geese, mouse-mice, knife-knives). These are called irregular plural nouns.

There are words that have Latin plurals and some that also have English plurals:

alga: algae

medium: media

vertebra : vertebrae, vertebras

index : indices, indexes