The usual construction of plural nouns from singular nouns is to add –s or –es to the end of a word.
Singular | Plural |
bird | birds |
dog | dogs |
cat | cats |
glass | glasses |
house | houses |
kindness | kindnesses (add –es to words that end in –s.) |
How do you know when to add –s or –es? If a noun ends in any ending but an –s or –ss, add –es to the end of that word to form the plural. Also, If a word ends in ch, sh, x, or z, add –es to the end of the noun:
Singular | Plural |
lunch | lunches (add -es) |
countess | countesses (add -es) |
lens | lenses (add -es) |
fish | fishes (add -es) |
fox | foxes (add -es) |
buzz | buzzes (add -es) |
If a word ends in –y, change the y to i and then add –es to create the plural, as shown below.
Singular | Plural |
baby | babies |
sky | skies |
library | libraries |
Please note the irregular plural nouns, shown in the following table.
Singular irregular nouns | Plural irregular nouns |
child | children |
foot | feet |
goose | geese |
man | men |
moose | moose |
mouse | mice |
ox | oxen |
woman | women |
Hyphenated nouns are pluralized by adding –s to the noun. In the examples below, law is also a noun. If a word is most likely to be multiplied, it takes the plural; thus, it is not that there is one mother and many laws, but many mothers.
Singular irregular nouns | Plural irregular nouns |
mother-in-law | mothers-in-law |
father-in-law | fathers-in-law |
sister-in-law | sisters-in-law |
brother-in-law | brothers-in-law |
For words that are derived from foreign languages, watch the singular and plural for proper use. If a Latin word, for instance, ends in –um, it will change to –a; a word ending in –us will change to –i.
Singular Latin word | Plural Latin word |
alumna | alumnae (female) |
alumnus | alumni (male) (gender neutral, informal: alum) |
datum | data |
erratum | errata |
medium | media |
memorandum | memoranda or memorandums |
phenomenon | phenomena |
stimulus | stimuli |
Exceptions exist, of course. Consult a dictionary for the proper use of singular and plural Latin-derived nouns.