Plural of Knife

search our site by Craig Shrives

The Plural of Knife

The plural of "knife" is "knives."

• Great knives will enable you to cut precisely. Knife skills are essential in cooking. (Eric Ripert)
• I've had people turn up to book signings with knives and guns. (Patricia Cornwell)

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

Are You Good at Plurals?

Here's a quick test.

Getting ready...

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	storey () donkey	add s	storeys donkeys
Nouns ending f or fe	dwarf knife	ves and/or s (There are no rules - you have to know.)	dwarfs knives
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

Read more about English spelling rules.

Why Is There Confusion over the Plural of Knife?

There is confusion because the rule for forming plurals with nouns ending in "f" or "fe" isn't straightforward. Most nouns will drop the "f" or "fe" and gain a "ves." For example:

• "Wife" becomes "wives."
• "Leaf" becomes "leaves."

Some just add s. For example:

• "Safe" becomes "safes."
• "Chief" becomes "chiefs."

With some words, both versions are accepted. For example:

• "Scarf" becomes "scarfs" or "scarves."
• "Dwarf" becomes "dwarfs" or "dwarves."

The plural of "knife" is always "knives." Unfortunately, there is no clever way of knowing which nouns ending "f" or "fe" follow which rules. You have to know.

Ready for the Test?