Singular and Plural Words — Complete List with Rules

Rule 1: Add -S to most nouns. • book → books, pen → pens, car → cars, tree → trees

Rule 2: Add -ES to nouns ending in -s, -ss, -sh, -ch, -x, -z. • bus → buses, class → classes, bush → bushes, bench → benches, box → boxes

Rule 3: Nouns ending in consonant + Y → change Y to I, add -ES. • baby → babies, city → cities, story → stories, fly → flies Exception: vowel + Y → add -S only: boy → boys, key → keys, toy → toys

Rule 4: Nouns ending in -F or -FE → change to -VES (usually). • leaf → leaves, wife → wives, knife → knives, shelf → shelves, wolf → wolves Exceptions (add -S): roof → roofs, chief → chiefs, proof → proofs, cliff → cliffs

Rule 5: Nouns ending in -O. • Most add -ES: hero → heroes, potato → potatoes, mango → mangoes, tomato → tomatoes • Music/foreign words add -S: piano → pianos, photo → photos, video → videos, zoo → zoos

Rule 6: Compound nouns — usually pluralise the main/principal noun. • mother-in-law → mothers-in-law, passer-by → passers-by, commander-in-chief → commanders-in-chief

Vowel changes: • man → men • woman → women • child → children • tooth → teeth • foot → feet • goose → geese • mouse → mice • louse → lice • ox → oxen

Same in singular and plural (unchanged): • sheep → sheep • deer → deer • fish → fish (or fishes for different species) • species → species • aircraft → aircraft • furniture → furniture (uncountable — no plural) • information → information (uncountable) • advice → advice (uncountable) • news → news (takes singular verb) • scissors → scissors (always plural) • trousers → trousers (always plural) • spectacles → spectacles (always plural)

Greek/Latin origin: • analysis → analyses • basis → bases • crisis → crises • thesis → theses • bacterium → bacteria • curriculum → curricula • datum → data • formula → formulae/formulas • medium → media • criterion → criteria • phenomenon → phenomena • alumnus → alumni • cactus → cacti/cactuses • fungus → fungi • syllabus → syllabi/syllabuses • radius → radii • nucleus → nuclei • appendix → appendices

Singular → Plural:

1. apple → apples
2. bench → benches
3. city → cities
4. day → days
5. echo → echoes
6. flower → flowers
7. glass → glasses
8. hero → heroes
9. inch → inches
10. journey → journeys
11. knife → knives
12. leaf → leaves
13. mango → mangoes
14. navy → navies
15. ox → oxen
16. piano → pianos
17. quantity → quantities
18. roof → roofs
19. scarf → scarves/scarfs
20. thief → thieves
21. umbrella → umbrellas
22. volcano → volcanoes
23. wish → wishes
24. yacht → yachts
25. zoo → zoos
26. child → children
27. woman → women
28. goose → geese
29. tooth → teeth
30. foot → feet
31. mouse → mice
32. sheep → sheep
33. deer → deer
34. criterion → criteria
35. phenomenon → phenomena
36. bacterium → bacteria
37. analysis → analyses
38. basis → bases
39. thesis → theses
40. radius → radii
41. formula → formulae
42. medium → media
43. cactus → cacti
44. fungus → fungi
45. nucleus → nuclei
46. axis → axes
47. index → indices/indexes
48. alumnus → alumni
49. memorandum → memoranda
50. stratum → strata