keen

keen — adjective

1. feeling or showing a strong desire to take part in an activity or to see somethi

1.形容詞B1
釋義

feeling or showing a strong desire to take part in an activity or to see something happen, often accompanied by active interest and effort.

例句

Layla is keen to join the school debate team next term.

keen + to + infinitive for personal desire

Stefan has always been keen on cycling and rides every weekend.

keen + on + gerund for enjoying an activity

同義詞
  • eager

    more about impatience or excitement for a future event than ongoing interest

  • enthusiastic

    suggests livelier, more energetic interest than keen

  • avid

    stronger and more consuming interest, often in a hobby

  • zealous

    implies intense, sometimes extreme commitment

反義詞

文法句型

keen + to + infinitive

keen + on + gerund/noun

用法筆記

In British English, 'keen on doing something' is a common everyday pattern. In American English, 'eager to' or 'enthusiastic about' are more typical for this sense.

常見錯誤

I am keen on go to the cinema.
I am keen on going to the cinema.' or 'I am keen to go to the cinema.
💡After 'keen on,' use a gerund (-ing form), not the base verb.

2. having a very strong or powerful effect, such as a feeling (disappointment, desi

2.形容詞B2
釋義

having a very strong or powerful effect, such as a feeling (disappointment, desire) or a situation (competition, rivalry) that involves deep intensity.

例句

The two runners share a keen rivalry that makes every race exciting.

keen + rivalry for intense competition

Padma felt a keen sense of disappointment when her visa application was denied.

keen + sense of + emotion noun

同義詞
  • intense

    more general; keen adds a sharper, more personal quality

  • acute

    slightly more formal and suggests a finely penetrating quality

  • fierce

    stronger and more aggressive, especially for competition

反義詞

文法句型

keen + noun

用法筆記

This sense often pairs with abstract nouns describing feelings (disappointment, regret, desire) or competition (rivalry, contest, competition). It cannot describe physical sensations like pain.

常見錯誤

I have a keen headache.
I have a bad headache.
💡Keen does not describe physical pain; use 'sharp' or 'intense' for pain instead.

3. able to think quickly, notice small differences, or perceive things with great a

3.形容詞B2
釋義

able to think quickly, notice small differences, or perceive things with great accuracy — for example, a person with a keen mind solves problems fast, and a keen eye spots tiny details that others miss.

例句

Mira has a keen eye for colour and always picks the perfect paint shade.

keen + eye for perception of detail

A keen sense of smell helps the dog find food buried beneath the snow.

同義詞
  • sharp

    more informal and common in everyday speech

  • acute

    more formal; often used for senses like hearing or sight

  • perceptive

    focuses on understanding people and situations well

反義詞

文法句型

keen + noun (mind / eye / sense)

用法筆記

Keen here describes the quality of a mental ability or physical sense — you have a 'keen mind' or 'keen eyesight,' not 'a keen person' (which would mean enthusiastic).

常見錯誤

She is a keen student' (ambiguous — could mean enthusiastic or sharp-minded).
She has a keen mind for mathematics.
💡Use 'keen + ability noun' to clearly mean sharp-minded.

4. (of wind or cold air) blowing with sharp force and a very low temperature, often

4.形容詞C1
釋義

(of wind or cold air) blowing with sharp force and a very low temperature, often cutting through clothing and making the skin feel as if it is being cut.

例句

A keen wind blew across the beach, forcing everyone to put on their jackets.

keen + wind for strong, cold air

The keen cold of the mountain air made Amani's fingers go numb within minutes.

同義詞
  • biting

    more common in everyday use; suggests a sharp, stinging quality

  • piercing

    emphasises the wind's ability to cut through clothing

  • icy

    focuses on low temperature rather than force

反義詞

文法句型

keen + wind / cold / air

用法筆記

Only used for wind, cold, or frosty air. Not used for rain, snow, or other weather conditions. 'Biting' or 'piercing' are more common alternatives.

常見錯誤

The rain was keen this morning.
The wind was keen this morning.
💡Keen describes wind or cold, not rain.

5. of a cutting tool or blade — made with a thin, sharp edge that can slice through

5.形容詞B2
釋義

of a cutting tool or blade — made with a thin, sharp edge that can slice through materials such as food, wood, or fabric without requiring much force, found mainly in formal or descriptive writing about knives and tools.

例句

The old knife still has a keen blade that slices through tomatoes with ease.

Kenji sharpened the axe until its edge was as keen as a razor.

keen + edge/blade for physical sharpness

同義詞
  • sharp

    the everyday word for cutting ability; keen is more literary

  • razor-sharp

    emphasises an extremely fine edge

反義詞

文法句型

keen + blade / edge / knife

用法筆記

Mainly used in formal, literary, or descriptive writing. In everyday speech, 'sharp' is far more common than 'keen' for describing cutting tools.

常見錯誤

Pass me the keen knife.
Pass me the sharp knife.
💡In conversation, use 'sharp' instead of 'keen' for cutting tools.

keen — verb

keen — noun