Singular Noun Definition:  When a noun means one only, it is said to be singular.  
Examples:  boy, girl, book, church, box

Plural Noun Definition:  When a noun means more than one, it is said to be plural.  
Examples:  boys, girls, books, churches

Rule #1
The plural of nouns is usually formed by adding - s to a singular noun.

Exercise:  Write the plural of each of these nouns

chair	star	farm
storm	door	rock
owner	paper	cup

Rule #2
Nouns ending in s, z, x, sh, and ch form the plural by adding - es.

Exercise:  Write the plural of each of these nouns

dress	brush	hex
wish	class	fox
cross	bench	bush
ax	grass	mantis

Special Note:
If you add - s to such nouns as fox, bush, and bench, you will find that you cannot pronounce them without making an additional syllable.  This is why such nouns form the plural by adding - es.

Quick Review

Exercise:  Tell if the following nouns are singular or plural

box	cats	slipper	forks	books
chair	desk	houses	paper	wagon
lamps	shoes	garden	horses	dress
dog	carts	kitchen	pony	glass

Exercise:  Write the plural of the following nouns

chair	star	pencil	girl	boy
ax	bush	coat	tree	bench
sketch	owner	touch	latch	mug

Exercise:  Write the singular of the following nouns

bells	churches	wagons	coals	pictures
clocks	boxes	kitchens	basins	chairs
days	houses	pencils	trees	tables

Rule #3
Nouns ending in - y preceded by a consonant is formed into a plural by changing - y to - ies.  
Examples:  lady, ladies; city, cities; army, armies

Exercise:  Write the plural of the following words

fly	baby	pony	injury	cherry
lady	beauty	story	history	berry
city	sky	duty	study	theory

Rule #4
Nouns ending in y preceded by a vowel form their plurals by adding - s.  
Example:  boy, boys; day, days

Exercise:  Write the plural of the following words

day	toy	essay	turkey	chimney
play	joy	valley	alley	volley

Rule #5
Most nouns ending in o preceded by a consonant is formed into a plural by adding es.  Example:  hero; heroes; grotto, grottoes

Exercise:  Write the plural of the following words

motto	calico	buffalo	hero
potato	cargo	volcano	grotto
mosquito*	tomato	halo*	tornado*
buffalo*	portico*	veto

*may add - s or - es

The following are among those that add s only

canto	solo	piano	lasso
halo	memento	albino	sirocco

Special Note:
Most nouns ending in o preceded by a vowel is formed into a plural by adding - s.
Example:  folio, folios; cameo; cameos; studio, studios; portfolio, portfolios

Rule #6
Some nouns ending in f or fe are made plural by changing f or fe to - ves.  
Example:  beef, beeves; wife, wives

Exercise:  Write the plural of the following words

calf	self	leaf	sheaf	life
loaf	shelf	half	wolf	knife
elf	half	thief	wife	gulf
chief	dwarf*	proof	turf

The following form their plurals by adding - s.

chief, chiefs	fife, fifes	mischief, mischiefs	hoof, hoofs
roof, roofs	grief, griefs	kerchief, kerchiefs	safe, safes

IRREGULAR PLURALS

man, men	foot, feet	mouse, mice
woman, women	tooth, teeth	louse, lice
child, children	ox, oxen	goose, geese

The following nouns have no singular:

scissors	oats	tongs	dregs
trousers	pinchers	bellows	snuffers
cattle	shears	measles	mumps
victuals	tweezers	vespers

Some nouns are always singular.  Some of these nouns may be used in the  plural when different kinds are meant as sugars, coffees, cottons

gold	silver	wheat	corn
molasses	copper	sugar	cotton

Singular nouns use this and that.

Plural nouns use these and those.