Irregular Plurals in English
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In a previous lesson, you saw the regular plurals of nouns in English. You also saw words that change how you pronounce and spell the ending.
In this lesson, we will see irregular plural forms.
It is difficult to tell when a word has an irregular plural. The best way to learn them is to memorize the singular and plural forms together.
Let’s look at the irregular plural of common words.
Review: Change in Pronunciation in the Irregular Spelling
Sometimes there is a change in the pronunciation of the ending F or FE for some words, and you add -es to the end of those words. Other times, there is no change in pronunciation or spelling.
For nouns ending in F or FE, there are three ways to make the plural.
1. The F or FE changes to -ve before adding -s, so there is a change pronunciation of the ending.
knife - knives
life - lives
2. However, you just add -s to the end of some words, so the plural is completely regular.
chef - chefs
roof - roofs
3. Some nouns have both forms.
scarf - scarfs or scarves
For more examples of this type of plurals, see the lesson on regular plurals.
No Change in the Plural
Some words do not change in the singular and plural.
Words ending in -craft (meaning small boat or vessel)
one craft - many craft
one aircraft - many aircraft
one spacecraft - many spacecraft
one deer - many deer
one fish - many fish
one moose - many moose
one sheep - many sheep
one shrimp - many shrimp
one species - many species
one salmon - many salmon
one series - many series
Irregular Plurals with Word Change
Some words do not end in -s or -es in the plural form.
one child - many children
one foot - many feet
one goose - many geese
one man - many men
one ox - many oxen
one man - many men
one mouse - many mice
one tooth - many teeth
Words formed using one of the above words keep the irregular plural.
one grandchild - many grandchildren
one schoolchild - many schoolchildren
one policeman - many policemen
one policewoman - many policewomen
Many words in English come from other languages (e.g., Latin, Greek, French). Many of such borrowed words kept the plural forms from the original language.
Singular -us becomes -i in the plural (pronounced as the word “I”)
- cactus - cacti
- fungus - fungi
- syllabus - syllabi
Singular -a becomes -ae
- formula - formulae (pronunced as the “e” in “me”) (formulas is also correct)
- vertebra - vertebrae (pronunced as the “ey” in “hey”) (vertebras is also correct)
- larva - larvae (pronounced as the “e” in “me”)
Singular -ix becomes -ices or -es
- appendix - appendices (appendixes is also correct)
- index - indices
- vortex - vortices
Singular -on or -umbecomes a
- bacterium - bacteria
- criterion - criteria
- medium - media
Singular -is becomes -es (pronounced as the “ees” in “fees”)
- analysis - analyses
- basis - bases
- crisis - crises
- diagnosis - diagnoses
- emphasis - emphases
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