Latin Plurals in English

Level 2

Latin plurals still live in English.

How It Works

SingularPluralChange
alumnusalumni-us to -i
radiusradii-us to -i
datumdata-um to -a
curriculumcurricula-um to -a
formulaformulae-a to -ae

English also accepts formulas and curriculums. A woman who studied at a school is an alumna, and several women are alumnae.

The rule helps with Latin too. When you meet curricula in a Latin sentence, it is a neuter plural: more than one curriculum.

The final i of a Latin plural sounds like ee. English says alumni and radii with a long i, but Latin says ah-LOOM-nee and RAH-dee-ee.

Examples (5)

  1. Alumnus in schola cantat.

    The pupil sings in school.

    Alumnus is singular. Latin alumnus means a foster child or pupil.

  2. Alumni in schola cantant.

    The pupils sing in school.

    Alumni is the plural, from -us to -i, and the verb is plural too.

  3. Radii in rota sunt.

    The spokes are in the wheel.

    Radius means a spoke or a ray. Its plural is radii.

  4. Curricula in circo sunt.

    The races are in the circus.

    Curriculum is neuter, so the plural ends in -a.

  5. Formulae in libro sunt.

    The rules are in the book.

    Formula is a first declension noun, so the plural ends in -ae.

Common Mistakes

  • Treating a neuter noun in -um like a masculine noun in -us.

    Curriculi in circo sunt.
    Curricula in circo sunt.

    Curriculum is neuter, so its plural ends in -a. Curriculi is a different form: of the race.

  • Giving radius the neuter plural.

    Radia in rota sunt.
    Radii in rota sunt.

    Radius is masculine, so its plural is radii.

How It Connects

Tap a pattern to see what it builds on and what it leads to.

Latin Plurals in EnglishLevel 2

Learn This First

English keeps some Latin plurals, so plural nouns and neuter plurals come first.

Words in This Pattern

alumnusdatumformulacurriculumradius