Office of Communications

Plurals

The following guidelines apply when forming and using plural words:

• Most words: Add s: students; professors; buildings.
• After a hard ch, add only s: monarchs.
• Words ending in ch, s, sh, ss, x and z: Add es: benches; dresses; boxes.
• Words ending in is: Change is to es: thesis/theses; crisis/crises; parenthesis/parentheses.
• Words ending in y: If y is preceded by a consonant or qu, change y to i and add es: babies; cities; synergies. Common nouns ending in y preceded by a vowel take only the s: alloys; days; attorneys.
• Words ending in o: If o is preceded by a consonant, most plurals require es: tomatoes; echoes. Words ending in o, directly after a vowel, take the s: folios; radios. Pianos is an exception.
• Some words ending in f, add s: briefs; reefs; roofs. Other words ending in f have irregular plurals with ves: hooves; shelves; lives.
• Proper Names: The plurals of most proper names are formed by adding s: the Greens, the Browns, the McDermotts. If the name ends in s or z, form the plural by adding es: the Rosses, the Rodriguezes, the Charleses. In forming plurals of proper names ending in y, ordinarily keep the y: the Kennedys, the Lowrys and the Bradys. Some exceptions are: Alleghenies and Rockies.
• Some words are the same in the plural as in the singular: chassis, corps, deer, moose and sheep.
• Latin endings: Latin-root words ending in us change us to i: alumnus, alumni. Most ending in a change to ae: alumna, alumnae (formula, formulas is an exception). Most ending in um add s: memorandums, referendums, stadiums.

Possessives

• Plural nouns not ending in s, add ’s: the alumni’s newsletter, the children’s playground.
• Plural nouns ending in s, add only an apostrophe: the girls’ locker room, the students’ newspaper.
• Nouns that are the same in singular and plural are treated as plurals – chassis, corps, deer.
• Singular nouns not ending in s, add ’s: the book’s pages, the pen’s ink.
• Singular common nouns ending in s, add ’s unless the next word begins with s: the witness’s chair, the witness’ seat.
• If a singular proper noun ends in s, add an apostrophe: The University of Texas at Dallas’ campus.
• Pronouns: Personal interrogative and relative pronouns have several forms for the possessive that do not involve an apostrophe: mine, ours, your, yours, his, hers, its, theirs, whose. If you are using an apostrophe with a pronoun, make sure that the meaning calls for a contraction: you’re, it’s, there’s, who’s.