Plural of Key

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The Quick Answer

The plural of key is keys.

The Plural of Key

The plural of key is keys.

Instead of giving a politician the keys to the city, it might be better to change the locks. (Doug Larson)
One of the keys to happiness is a bad memory. (Rita Mae Brown)

The noun key adheres to the standard rules for forming the plurals of nouns in English (shown in the table below).

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The Standard Rules for Forming the Plurals

The table below shows the standard rules for forming the plurals of nouns in English.

Type	Example of Type	Forming the Plural	Plural
Most Nouns	lamp scythe	add s	lamps scythes
Noun Ending s, sh, ch, x or z	bus dress	add es	buses dresses
Nouns ending [consonant] o	hero zero tomato	add either s or es (There are no rules for this - you have to know.)	heroes zeros tomatoes
Nouns ending [vowel] o	patio ratio	add s	patios ratios
Nouns ending [consonant] y	story penny	change the y to an i and add es	stories pennies
Nouns ending [vowel] y	key chimney	add s	keys chimneys
Nouns ending f or fe	dwarf hoof	ves and/or s (There are no rules - you have to know.)	dwarfs hooves or hoofs
Exceptions	man louse	some nouns undergo a vowel or letters change	men lice
More exceptions	salmon sheep	some nouns do not change at all	salmon sheep

Why Is There Confusion over the Plural of Key?

Keys is the only way to make the noun key plural.

Confusion arises because some people mistakenly believe that all nouns ending in "y" should form a plural ending in "ies". When a noun ends with [vowel] + y, you only need to add an "s" to form the plural.

Another Interactive Exercise

Here are three randomly selected questions from another exercise on plurals, which can be edited, printed to create an exercise worksheet, or sent via email to friends or students.

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