plurals

Words ending in -ch, -s, -sh, -ss, -x, and -z; words ending in -is; words ending in -y; words ending in -o; words ending in -f; Latin endings; form change; words as words; proper names; figures; single letters; multiple letters/acronyms

Most words: Add -s. colleges. books.

Words ending in -ch, -s, -sh, -ss, -x, and -z: Add -es. dresses. matches. fixes. Exception: monarchs.

Words ending in -is: Change is to -es. parentheses. theses.

Words ending in -y: If y is preceded by a consonant or qu-, change y to i and add -es. armies. cities. soliloquies. Exception: proper names. For all other words ending in -y, add -s. donkeys.

Words ending in -o: If o is preceded by a consonant, -es is usually added to create a plural. See Webster’s for exceptions. potatoes. echoes. heroes. pianos.

Words ending in -f: In general, change f to v and add -es. leaves. selves. Exceptions: roofs. chiefs.

Latin endings: Latin-root words ending in -us change to -i. Those ending in an -a change to -ae. For words ending in -um, add -s. See Webster’s. alumni. alumnae. memorandums.

Form change: Some words change forms when they become plural. men (man). feet (foot). children (child). Note that when an -s follows these plurals, it is meant to show possession and thus needs an apostrophe. men’s. children’s.

Words as words: Add an -s. No ifs, ands, or buts.

Proper names: Add -es to proper names ending in -es, -s, or -z. The Evanses went on vacation. Add simply -s to those ending with a -y. the Kennedys. Exceptions: Alleghenies. Rockies.

Figures: Add -s. the 1920s.

Single letters: Add -’s to a single lowercase letter to make it plural. To make a single uppercase letter plural, add -s. the three Rs. p’s and q’s. (CMS 7.15 and 7.16)

Multiple letters/acronyms: Add -s. VIPs. MVPs. ABCs.

See also AP, Webster’s, and specific entries in this guide