sharpen

IPA/ˈʃɑːpən/
KK[ʃˈɑrpən]IPA/ˈʃɑːrpən/

sharpen — verb

  • sharpenpresent simple I / you / we / they
  • sharpenshe / she / it
  • sharpenedpast simple
  • sharpening-ing form

1. to rub or press a tool, blade, or pointed object against a hard surface so that

1.verbtransitive / intransitiveB1
Definition

to rub or press a tool, blade, or pointed object against a hard surface so that its cutting edge or tip becomes thinner and able to cut or pierce more easily.

Example

Wren spent the morning sharpening all the kitchen knives on a whetstone.

sharpen + noun + on + tool

The scissors were so blunt that Eli had to sharpen them before cutting the fabric.

sharpen + object that became blunt

Common collocations
  • sharpen a knife
  • sharpen a pencil
  • sharpen scissors
  • sharpen on a whetstone
  • sharpen with a file
Synonyms
  • hone

    more precise, usually on a fine stone for a very sharp edge

  • whet

    slightly old-fashioned; now used mostly in the phrase 'whet one's appetite'

  • grind

    removes more material; reshaping a blade rather than refining its edge

Antonyms
  • blunt

    to make a blade less sharp

Grammar Patterns

sharpen + noun phrase

sharpen + on + noun phrase

noun phrase + sharpen

Usage Note

The intransitive form describes how a tool behaves: 'This knife sharpens well.' The transitive form focuses on a person's action: 'She sharpened the knife.'

Common Mistakes

I sharped the pencil.
I sharpened the pencil.
'sharp' is an adjective; the verb form is 'sharpen.'
He sharpened the knife on the table.' (ambiguous)
He sharpened the knife on a whetstone.
specify the tool used for sharpening, not just any surface.

2. to make a physical or emotional feeling, sense, or mental ability stronger and m

2.verbtransitive / intransitiveB2
Definition

to make a physical or emotional feeling, sense, or mental ability stronger and more active — for example, making your appetite bigger, your hearing more sensitive, or your fear more intense.

Example

The long walk through the hills sharpened Hari's appetite for a warm meal.

sharpen + appetite

Years of working in a noisy factory had sharpened Megan's ability to read lips.

sharpen + ability to ...

Common collocations
  • sharpen the appetite
  • sharpen the senses
  • sharpen awareness
  • sharpen instincts
Synonyms
  • heighten

    more formal; often used for emotions and sensations

  • intensify

    stronger; can apply to feelings, colours, or efforts

  • accentuate

    more formal; suggests making something more noticeable

Antonyms
  • dull

    to make senses or feelings less sharp

  • blunt

    to reduce the strength of a feeling or response

Grammar Patterns

sharpen + noun phrase

noun phrase + sharpens

Usage Note

Common objects include appetite, senses, awareness, instincts, fear, and desire. The intransitive form describes feelings growing stronger on their own, without someone actively causing it.

Common Mistakes

The walk sharpened my hunger.
The walk sharpened my appetite.
'appetite' is the natural collocation for food; 'hunger' is more literal and less idiomatic here.
I sharpened my hearing by listening carefully.
The training sharpened my hearing.
native speakers typically use this sense with a situation or experience as subject, not a person as subject.

3. to practise and develop a skill or ability so that it becomes stronger, faster,

3.verbtransitiveB2
Definition

to practise and develop a skill or ability so that it becomes stronger, faster, or more effective — like improving your writing through regular exercises or your game through coaching.

Example

Xiu joined a summer workshop to sharpen her public speaking skills.

sharpen + skill type

Playing against stronger opponents helped João sharpen his chess tactics.

Common collocations
  • sharpen skills
  • sharpen abilities
  • sharpen reflexes
  • sharpen tactics
Synonyms
  • hone

    very close; 'hone' suggests finer, more precise improvement

  • refine

    suggests making small improvements to reach a higher standard

  • polish

    suggests final improvements to make something excellent

Antonyms
  • neglect

    to fail to practise or develop a skill

Grammar Patterns

sharpen + noun phrase

Usage Note

Subject is usually a person or an activity (course, practice, workshop). Common objects are skill-based: skills, techniques, abilities, reflexes, tactics, and talents. This sense overlaps with 'hone' in metaphorical use.

Common Mistakes

I sharpened my English.
I sharpened my English skills.
'sharpen' typically takes a skill-type noun rather than a language name directly.
The class sharpened my knowledge of history.
The class sharpened my ability to analyse historical events.
'sharpen' works better with an active skill than with stored information.

4. to make an image, idea, argument, or distinction clearer and easier to see or un

4.verbtransitiveB1
Definition

to make an image, idea, argument, or distinction clearer and easier to see or understand — for example, adjusting a camera lens so the picture stops being blurry, or stating a disagreement more precisely so everyone sees the difference.

Example

The photographer adjusted the lens to sharpen the image of the bird.

sharpen + image / photograph

The debate helped sharpen the differences between the two candidates' policies.

sharpen + difference / distinction

Common collocations
  • sharpen an image
  • sharpen the focus
  • sharpen a distinction
  • sharpen an argument
  • sharpen the contrast
Synonyms
  • clarify

    broader; can apply to any confusing situation or statement

  • focus

    common for images and attention; 'sharpen' is more about definition of edges

  • refine

    suggests improving precision or detail

Antonyms
  • blur

    to make an image or idea less clear

  • obscure

    to hide or make something difficult to see or understand

Grammar Patterns

sharpen + noun phrase

Usage Note

Common objects include image, focus, outline, distinction, difference, argument, and understanding. In photography and image-editing contexts, 'sharpen' is a specific technical action that increases edge contrast.

Common Mistakes

I sharpened the photo so it looks better.
I sharpened the edges of the photo so the details stand out.
'sharpen' in imaging is about edge contrast, not general improvement.
The teacher sharpened the lesson for us.
The teacher's explanation sharpened our understanding of the topic.
the object should be the idea or understanding, not the lesson itself.

5. to make a musical note sound higher, typically by one semitone, indicated by a ♯

5.verbtransitiveC1
Definition

to make a musical note sound higher, typically by one semitone, indicated by a ♯ symbol written before the note in sheet music.

Example

The composer wrote a sharp sign to tell the violinist to sharpen the F.

sharpen + musical note letter

To play in this key, you need to sharpen every B in the melody.

Common collocations
  • sharpen a note
  • sharpen the pitch
  • sharpen the F
  • sharpen the B
Synonyms
  • raise

    general term; 'sharpen' is the precise musical term for raising by a semitone

Antonyms
  • flatten

    to lower the pitch of a musical note

Grammar Patterns

sharpen + musical note / pitch

Usage Note

This sense is almost exclusively used in music contexts. The opposite is 'flatten' (lower the pitch). In everyday speech, non-musicians rarely use this sense.

Common Mistakes

Please sharpen that note a bit so it sounds louder.
Please sharpen that note so it sounds higher.
'sharpen' changes pitch, not volume.
The singer sharpened her voice.
The singer sharpened the final note of the phrase.
the object should be the specific note, not the voice itself.

Word family

Synonym discussion

Sense: verb/1

All four verbs describe making a blade sharper, but they differ in technique and current usage. 'Sharpen' is the general-purpose word — you can sharpen anything from a pencil to a kitchen knife on any suitable surface. 'Hone' is more specific: it means using a fine-grained stone to refine an already fairly sharp edge, and it is also common in metaphorical uses ('hone your skills'). 'Whet' once meant the same as sharpen but is now mostly limited to the fixed phrase 'whet one's appetite' (increase desire). 'Grind' involves removing more metal, often reshaping a damaged blade on a rough wheel. 'Strop' is the narrowest term: it refers to running a straight razor back and forth on a leather strap to align the edge between shaves. For everyday use, 'sharpen' is the right choice; 'hone' is best for precision work or figurative language.

hone ↗whet ↗grind ↗strop

Common collocations

Nouns

Adverbs

Phrases

  • sharpen up
  • sharpen one's skills
  • sharpen the focus
  • sharpen the contrast

Prepositions

Etymology

Proto-GermanicOld EnglishMiddle EnglishEnglish

'Sharpen' comes from Old English 'scearpian' (to make sharp), which developed from the Proto-Germanic adjective *skarpaz (cutting, sharp). The modern spelling emerged in Middle English, and the '-en' suffix is the common English way of forming verbs from adjectives meaning 'to make or become' (compare 'widen', 'deepen', 'strengthen'). The musical sense (raising pitch) developed later, from the early 17th century, when musicians began using 'sharp' to describe a note higher in pitch.

First known use

15th century

15th century, in the meaning defined at transitive sense