
Study Resource: English plural nouns reference sheet
The table below summarizes the rules for forming in English.
Noun Ending  | Plural Rule  | Singular  | Plural  | Notes  | 
Most regular nouns  | Add -s  | dogplant  | dogsplants  | Can be pronounced /s/ or /z/.  | 
-s, -ss, -sh, -ch, -x, -z…  | Add -es  | buschurchbox  | buseschurchesboxes  | An extra syllable is added.  | 
-f, -fe (only some nouns)  | -f / -fe → -ves  | knifeloaf  | knivesloaves  | Pronunciation of f changes too.   | 
-y (after a consonant)  | -y → -ies  | partycountry  | partiescountries  | No difference in pronunciation. After a consonant, just add -s.  | 
-o (only some nouns)  | Add -es  | tomatovolcano  | tomatoesvolcanoes  | No difference in pronunciation.  | 
Types of irregular nouns  | ||||
Some animals we hunt to eat  | NO CHANGE  | fishdeer  | fishdeer  | Used particularly for swimming sea creatures (fish), deer, and some game animals  | 
Words that end in -craft  | NO CHANGE  | aircraft  | aircraft  | Some nouns that end in -craft are mass nouns, so they have no plural (witchcraft, stagecraft...).  | 
Some old nouns  | Vowel change only  | mangoose  | mengeese  | List is very short: foot, man, woman, goose, mouse, tooth, louse.  | 
child, ox, brother  | Add -en  | childoxbrother  | childrenoxenbrethren  | Vowel changes in children and brethren too. Brethren is old and not used for genetic brothers.  | 
Nouns ending in -us  | -us → -i / -era  | syllabusgenus  | syllabigenera  | Usually only Latin nouns.  | 
Nouns ending in -a  | -a → -ae  | alumnaformula  | alumnaeformulae  | Usually only Latin nouns.  | 
Nouns ending in -ix or -ex  | -ix / -ex → -ices  | matrixvortex  | matricesvortices  | Usually only Latin nouns.  | 
Nouns ending in -um  | -um → -a  | datumminimum  | dataminima  | Usually only Latin nouns.  | 
Nouns ending in -is  | -is → -es  | thesisaxis  | thesesaxes  | Usually only Latin nouns.  | 
Nouns ending in -on  | -on → -a  | criterionautomaton  | criteriaautomata  | Usually only Greek nouns.  | 
Nouns ending in -au  | Add -x  | châteaubeau  | châteauxbeaux  | Usually only French nouns.  | 
There is also a short list of irregular nouns that you’ll just need to memorize. Mostly:
person → people
die → dice
penny → pence (in England)
