Nouns that take -es:
Nouns ending with -ch, -s, -sh, -x (xe) ,-z (ze), add -es:
- match --> matches
- glass --> glasses
- flash --> flashes
- tax --> taxes
- blaze --> blazes
Nouns that end in -o:
Most add -es:
- hero -->heroes
- potato --> potatoes
There are some exceptions:
- kangaroo --> kangaroos
- piano --> piano
- studio --> studios
- zoo --> zoos
Some can follow either form:
- buffalo --> buffalos or buffaloes
- cargo --> cargos or cargoes
- motto --> mottos or mottoes
- volcano --> volcanos or volcanoes
Nouns ending consonant + -y:
Change -y to -i and add -es:
- Baby --> babies
- Therapy --> therapies
Nouns that end in -f or -fe:
Change the -f to -v and add -es
- Leaf --> leaves
- Shelf --> shelves
NB: There are some exceptions:
- Belief --> beliefs
- Cliff --> cliffs
- Cuff --> cuffs
- Dwarf --> dwarfs
- Gulf --> gulfs
- Roof --> roofs
With loan words
Nouns ending -is:
Change -is to -es
- Analysis --> analyses
- Basis --> bases
- Thesis --> theses
Nouns ending -um:
Either change -um to -a
- Datum --> data
- Forum --> fora
NB- Nowadays, simply adding -s is often used (forums, etc), but less so with technical words, and never with 'datum'.
Nouns ending -on:
Change -on to -a:
- Criterion --> criteria
- Phenomenon --> phenomena
Nouns ending -a:
Add -e:
- Antenna --> anntennae
- Formula --> formulae
Nouns ending -ex or -ix
Replace the last two letter with -ices:
- Appendix --> appendices
- Index --> iindices
Nouns ending -us:
There are two ways we make the plural:
Replace the last two letters with -i:
- Stimulus --> stimuli
Replace the last two letters with -a:
- Corpus --> corpora
Nouns ending -eau:
Add -x
- Bureau --> bureaux