Changing the spelling of singular noun:
For Examples:
- person - people
- ox - oxen
- man - men
- woman - women
- caveman - cavemen
- policeman - policemen
- child - children
- tooth - teeth
- foot - feet
- goose - geese
- mouse - mice
- mouse – lice
Some nouns use the same singular and plural form:
For Examples:
- aircraft - aircraft
- barracks - barracks
- deer - deer
- gallows - gallows
- moose - moose
- salmon - salmon
- hovercraft - hovercraft
- spacecraft - spacecraft
- series - series
- species - species
- means - means
- offspring - offspring
- deer - deer
- fish - fish
- sheep - sheep
Some nouns are of Latin/Greek/French Origin:
For Examples:
Nouns of Latin Origin:
- alumnus - alumni/alumnuses
- apex - apices/apeces
- appendix - appendices/ appendixes
Nouns of French Origin:
For Examples:
- chateau - chateaux/chateaus
- bureau - bureaux/ bureaus
- tableau - tableaux/tableaus
Nouns of Greek Origin:
For Examples:
- diagnosis - diagnoses
- ellipsis - ellipses
- hypothesis - hypotheses
- oasis - oases
They are very useful