Is “knife” singular or plural?
The chef sharpened all his knives before cooking.
He accidentally cut his finger with a sharp knife.
Please put the dirty knife in the dishwasher.
She bought a set of new knifes for her kitchen.
Knife is singular; knives is plural. What’s with the word knife, and why does it behave the way it does from its singular to plural form? Keep reading.
What’s the definition of “knife”?
The online dictionary defines the word knife as, “an instrument for cutting, consisting essentially of a thin, sharp-edged, metal blade fitted with a handle”.
What’s the plural of knife?
The plural of knife (knives), is irregular. Though it ends in the regular –es as a plural noun, it does so by replacing its ending (-fe) in the singular case. Nouns normally add on the -es/-s to show plurality: books, phones, dogs and cats all put an s to demonstrate a plural noun. This makes it extremely easy (for the most part) to form a plural noun: just add an s to the singular noun.
This isn’t the case with words leaf, wolf shelf, elf, life, wife, thief, calf, half, (the list goes on.) It could have something to do with the fact that each of these words came to Modern English from the Germanic languages, or PIE (Proto-Indo-European languages.) The same rule that applies with these other Germanic derived nouns, (wolf, knife, wife, life, etc.) each ends in –ves as a plural noun, replacing the sibilant -f/-fe in the singular case. See the chart below.
Nouns that end in -f/-fe and -ves
| singular | plural |
| knife | knives |
| life | lives |
| wife | wives |
| shelf | shelves |
| self | selves |
| half | halves |
| wolf | wolves |
Visualize multiple “knives” slicing through the letter “f” in “knife,” turning it into “ves,” to remember the plural form: “knives.”.
Examples of “knife” (singular), in sentences
1. This knife has no sharp edge.
2. The man attacked him with a knife.
3. We usually eat with a knife, fork and spoon.
4. I injured myself with a sharp knife.
5. Drop the knife!
Examples of “knives” (plural), in sentences
1. I’ll get the knives and forks out to set the table for dinner.
2. Bread knives should have a serrated edge.
3. Knives of any description are forbidden.
4. The men were carrying knives and clubs.
5. Put the knives in the kitchen drawer.
Synonyms for knife
- blade
- cutter
- bayonet
- scalpel
- skewer
- sword
- scythe
- sickle
- lance
- machete
Origin of knife
From etymonline on knife:
“hand-held cutting instrument consisting of a short blade and handle,” late Old English cnif, probably from Old Norse knifr “knife, dirk,” from Proto-Germanic *knibaz.“
What’s the difference between they’re, their, and there?
Work Sheet
What is the correct plural form of the word “knife”?
According to the blog post, which is the *incorrect* plural form of “knife”?
The post mentions that many nouns ending in -f or -fe change their ending to what in the plural form?
Which of the following words listed in the post forms its plural similarly to “knife”?
According to the post, which example sentence correctly uses the *singular* form of knife?
He accidentally cut his finger with a sharp .
Based on the blog post’s example of an incorrect sentence needing the plural: Please put the dirty in the dishwasher.
The chef sharpened all his before cooking.
Based on the blog post’s example of an incorrect sentence needing the plural: She bought a set of new for her kitchen.
I’ll get the and forks out to set the table for dinner.
Frequently Asked Questions
What is the plural of knife?
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Is “knifes” the correct plural?
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How is the plural “knives” formed?
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When do I use knife versus knives?
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Are other nouns plural like knife?
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Yash, D. "What’s the Plural of Knife?." Grammarflex, Jun 6, 2025, https://www.grammarflex.com/whats-the-plural-of-knife/.
Sources
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Definition of knife.
