Learn the rules of plural formation and the most common exceptions.

For advanced irregular plurals you can see this other video:

Irregular Plurals in English: Basic & Advanced

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.
Example: lamp, lamps; cat, cats; fork, forks; flower, flowers; pen, pens

Rule #2
Nouns ending in s, z, x, sh, and ch form the plural by adding es.
Example: moss, mosses buzz, buzzes box, boxes
dish, dishes church, churches

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.

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

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

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

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

Some words are irregular. Some important ones are:
- man / men
- woman / women
- child / children
- foot / feet
- tooth / teeth
- wolf / wolves
- knife / knives
- policeman / policemen
- fireman / firemen
- person / people