PLURAL NOUNS EXERCISE 3 — IRREGULAR FORMS (ESL)

Grammar review Irregular plural nouns — the main patterns

Irregular plural nouns don’t follow the standard -s/-es pattern. They fall into recognisable groups, which makes them easier to learn once you know the categories.

Vowel change (the most common irregular pattern):
The vowel in the middle of the word changes. This group includes some of the most common nouns in English — body parts, animals, and people words are well represented here.
louse → lice is a less common example of this pattern you may not have seen before.

Completely irregular:
A small number of nouns have plurals that follow no predictable pattern and must simply be memorized. One of the most common English words for a young person falls into this category.

Same form for singular and plural:
Some nouns don’t change at all between singular and plural. Context tells you which is meant. This group includes several animal names and some technical/scientific words.

Latin/Greek origin nouns:
Many academic and scientific words in English come from Latin or Greek and keep their original plural forms.
The singular endings -um, -on, -is, -us, -a often have specific plural forms that must be memorized. Cactus → cacti is one example of this pattern.

How to approach this exercise:
For each noun, ask: does it belong to one of the groups above? Think about whether you’ve heard or seen the plural before — many of these forms appear regularly in everyday speech and academic writing.