A noun is a word for a person, place, or thing that can be the subject of a verb. One of the first things you learn in a new language are nouns. Different languages have different ways to make a singular noun plural.
In English, the most common way to make a noun plural is to add the letter s:
 pen: pens
 spoon: spoons
 table: tables
 letter: letters
 window: windows
 
 Nouns ending in tch, s (or ss), or x are often made plural with the letters es:
 tax: taxes
 match: matches
 bus: buses
 business: businesses
 
 Some nouns ending in f replace the f with v, ending in ves:
 shelf: shelves
 knife: knives
 self: selves
 thief: thieves
 
 Some nouns have irregular plurals:
 man: men
 woman: women
 child: children
 foot: feet
 ox: oxen
 
 Some nouns ending in y drop the y and are made plural with ies:
 university: universities
 baby: babies
 But if the y has another vowel before it, then usually the plural is made by adding s:
 boy: boys
 monkey: monkeys
 
 Nouns ending in o are irregular. Some end with s, some with es, and some work with both:
 hero: heros or heroes
 volcano: volcanos or volcanoes
 
 Some nouns have the same singular and plural forms, and most of these are animals: moose, deer, fish, swine
 
 Further Learning
 This example from Yabla English has 5 different plural nouns, including two that are irregular:
We have brought a set of consulting tools
that include analyses, evaluation criteria,
business processes and governance recommendations.
Captions 9-11, Planview and Kalypso - Partner to Drive Innovation
Play Caption
Try to correctly change the four nouns to their singular form and check your work to see if you converted the two irregular nouns correctly.
 
 For even more plurals, watch the Yabla English video English with Lauren and Matt - Parts of the Human Body.