Meaning
The kanji 硬 (kō, kata.i) signifies “hard,” “stiff,” “solid,” or “unyielding.” You'll often find this character describing physical hardness, rigidity, or firmness. It can also extend to abstract concepts such as stubbornness or firmness in one's attitude. Essentially, it describes a lack of flexibility or resistance to external forces.
The structure of 硬 reveals its meaning. It consists of two main parts: 石 (ishi), meaning “stone,” on the left, and 更 (kō), meaning “further” or “again,” on the right. The radical 石 clearly points to hardness, as stone is an inherently hard and solid material. The right component 更 acts phonetically, giving the kanji its on'yomi reading of コウ. It also adds a semantic nuance of 'more' or 'increasingly,' suggesting something thoroughly or enduringly hard. This combination of a hard material like stone with the idea of 'further' emphasizes extreme hardness or solidity. With 12 strokes, 硬 is taught in the 8th grade in Japan, highlighting its importance in advanced Japanese vocabulary.
Readings
On'yomi (音読み) — Chinese-derived readings
The main on'yomi reading for 硬 is コウ (kō). You'll typically find this reading in compound words, especially those with more formal or technical implications, where it signifies hardness, firmness, or rigidity.
- 硬度 (kōdo) — hardness; rigidity
- 硬貨 (kōka) — coin; hard currency
- 硬直 (kōchoku) — rigidity; stiffness; deadlock
Kun'yomi (訓読み) — Native Japanese readings
The main kun'yomi reading for 硬 is かた.い (kata.i), which is found in the adjective 硬い (katai) and its variations. It appears in words describing physical hardness or firmness, and sometimes even mental steadfastness.
- 硬い (katai) — hard; solid; stiff; firm; unyielding
- 硬くなる (kataku naru) — to become hard; to stiffen
- 硬める (katameru) — to harden; to solidify (transitive verb)
Common Words & Compounds
The kanji 硬 appears in numerous words, encompassing various aspects of hardness, stiffness, and firmness.
Physical Attributes
- 硬質 (kōshitsu) — hard quality; hard (e.g., hard wood, hard water)
- 硬球 (kōkyū) — hardball (in baseball)
- 硬水 (kōsui) — hard water
- 硬骨魚 (kōkotsugyo) — bony fish
Abstract & Figurative Use
- 強硬 (kyōkō) — firm; rigid; unbending; resolute
- 硬派 (kōha) — hard-liner; tough-minded person; orthodox faction
- 硬論 (kōron) — hard argument; firm opinion
Materials & Objects
- 硬紙 (kōshi) — cardboard; stiff paper
- 硬木 (kōboku) — hardwood
- 硬度計 (kōdokei) — hardness meter
Example Sentences
このテーブルは硬い木でできています。
Kono tēburu wa katai ki de dekiteimasu.
This table is made of hard wood.
彼はどんなに説得しても、硬い決意を変えなかった。
Kare wa don't nani settoku shite mo, katai ketsui o kaenakatta.
No matter how much we persuaded him, he did not change his firm resolve.
地震で地面が硬く揺れた。
Jishin de jimen ga kataku yureta.
The ground shook firmly during the earthquake.
新しい靴は少し硬くて、足が痛い。
Atarashii kutsu wa sukoshi katakute, ashi ga itai.
The new shoes are a bit stiff, so my feet hurt.
硬貨を貯金箱に入れる。
Kōka o chokinbako ni ireru.
I put a coin in the piggy bank.
彼の意見はいつも非常に強硬だ。
Kare no iken wa itsumo hijō ni kyōkō da.
His opinion is always very firm.
古いパンは硬くなってしまった。
Furui pan wa kataku natte shimatta.
The old bread has become hard.
この石はとても硬度が高い。
Kono ishi wa totemo kōdo ga takai.
This stone has very high hardness.
冷凍庫から出したアイスクリームはまだ硬すぎる。
Reitōko kara dashita aisukurīmu wa mada katasugiru.
The ice cream taken out of the freezer is still too hard.
Memory Tip
To remember 硬 (hard, stiff), consider its components: 石 (stone) and 更 (further, again). Visualize a stone that grows increasingly hard and stiff, as if repeatedly reinforced or compacted 'further' to achieve ultimate rigidity. This image of an unyielding stone can help you solidify the meaning of 'hard' or 'stiff'. The 'stone' radical provides the core concept of hardness, while 'further' implies an intensified degree of that quality, making the kanji effectively convey 'extremely hard' or 'solid like a rock'.