不 — Not, Un-, In-

Meaning

The kanji 不 (fu, bu) is a fundamental character in Japanese. It primarily conveys the meaning of 'not,' 'un-,' 'in-,' or 'non-'. As a versatile prefix, it transforms positive concepts into their negative counterparts. When attached to another kanji or word, it creates a sense of absence, impossibility, dissatisfaction, or a general lack of something.

Its etymological origin is widely debated. One popular theory suggests that 不 originally depicted a bird flying upwards. However, a horizontal line was added, signifying an obstacle or barrier the bird 'cannot' cross. This imagery then led to the meaning of 'not' or 'cannot.'

Another perspective sees 不 as a stylized representation of a plant failing to sprout or grow upwards, again conveying negation or failure. Regardless of the exact pictographic origin, the central idea of something being prevented, absent, or contrary to expectation remains consistent with its meaning.

Visually, the kanji 不 is composed of four strokes. The top horizontal stroke (一) can be seen as a boundary or limit. The subsequent strokes suggest something attempting to move past this limit but ultimately failing. This structure embodies the idea of negation or 'not.' While structurally simple, 不 carries significant meaning in the Japanese language.

This kanji is part of the JLPT N4 curriculum. It is typically introduced to Japanese schoolchildren in the 4th grade, underscoring its importance in basic literacy.

Readings

On'yomi (音読み) — Chinese-derived readings

The on'yomi readings of 不 are derived from its historical pronunciation in Chinese. They are almost exclusively used when 不 appears in compound words with other kanji. There are two main on'yomi readings: フ (fu) and ブ (bu).

フ (fu)

This is the more common on'yomi reading for 不. You'll find it in many compounds, especially when 不 precedes kanji that start with sounds other than 'b' or 'p' (and sometimes even then). It functions as a clear negative prefix.

不安ふあん (fuan) — anxiety, uneasiness, apprehension (literally 'not peace')
不可能ふかのう (fukanō) — impossible, impracticable (literally 'not possible')
不要ふよう (fuyō) — unnecessary, unneeded (literally 'not need')
不公平ふこうへい (fukōhei) — unfairness, injustice (literally 'not fairness')
不確かふたしか (futashika) — uncertain, vague (literally 'not certain')

ブ (bu)

The reading ブ is less common than フ. It typically occurs due to phonetic assimilation when 不 precedes certain consonants, particularly labial consonants like 'p' or 'b', or sometimes 'k' or 'm'. This sound change often makes pronunciation smoother.

不便ふべん (fuben) — inconvenience, inexpedience (literally 'not convenient')
不満ふまん (fuman) — dissatisfaction, discontent (literally 'not satisfaction')
不器用ぶきよう (bukiyō) — clumsy, awkward (literally 'not skilled/dexterous')
不作ぶさく (busaku) — poor harvest, crop failure (literally 'not harvest/make')

Kun'yomi (訓読み) — Native Japanese readings

The kanji 不 does not have any commonly used kun'yomi (native Japanese) readings as a standalone word. It almost exclusively functions as a prefix within compound words, for which it adopts its on'yomi readings. This is typical for many kanji that serve primarily as grammatical prefixes rather than independent nouns or verbs.

Common Words & Compounds

The kanji 不 is incredibly versatile and forms numerous compound words, acting as a negative prefix. Here are some common examples, categorized for easier learning:

General Negation / Lack

不可能ふかのう (fukanō) — impossible
不要ふよう (fuyō) — unnecessary, unneeded
不確かふたしか (futashika) — uncertain, vague
不一致ふいっち (fuitchi) — disagreement, inconsistency
不足ふそく (fusoku) — insufficiency, shortage

Feelings & States

不安ふあん (fuan) — anxiety, uneasiness
不満ふまん (fuman) — dissatisfaction, discontent
不幸ふこう (fukō) — unhappiness, misfortune
不快ふかい (fukai) — unpleasantness, discomfort
不機嫌ふきげん (fukigen) — bad mood, ill humor

Conditions & Circumstances

不便ふべん (fuben) — inconvenience
不作ぶさく (busaku) — poor harvest, crop failure
不景気ふけいき (fukeiki) — recession, economic slump
不規則ふきそく (fukisoku) — irregularity, unruliness
不注意ふちゅうい (fuchūi) — carelessness, inattention

Skills & Qualities

不器用ぶきよう (bukiyō) — clumsy, awkward
不真面目ふまじめ (fumajime) — insincere, not serious

Example Sentences

今日は体調たいちょうが不調ふちょうなので、早はやめに帰かえります。

Kyō wa taichō ga fuchō nano de, hayame ni kaerimasu.

Today my physical condition is not good, so I'll go home early.

試験しけんの結果けっかに不満ふまんがありましたが、次つぎはもっと頑張がんばります。

Shiken no kekka ni fuman ga arimashita ga, tsugi wa motto ganbarimasu.

I was dissatisfied with the exam results, but I'll try harder next time.

この場所ばしょは交通こうつうが不便ふべんなので、車くるまがないと大変たいへんです。

Kono basho wa kōtsū ga fuben nano de, kuruma ga nai to taihen desu.

This place has inconvenient transportation, so it's tough without a car.

明日あしたの天気てんきは不確ふたしかですが、ピクニックは決行けっこうします。

Ashita no tenki wa futashika desu ga, pikunikku wa kekkō shimasu.

Tomorrow's weather is uncertain, but we'll go ahead with the picnic.

彼女かのじょは不器用ぶきようですが、とても真面目まじめな人ひとです。

Kanojo wa bukiyō desu ga, totemo majime na hito desu.

She is clumsy, but she is a very serious person.

その仕事しごとを一日いちにちで終おえるのは不可能ふかのうです。

Sono shigoto o ichinichi de oeru no wa fukanō desu.

It's impossible to finish that job in one day.

彼かれはいつも不注意ふちゅういで、よく物ものをなくします。

Kare wa itsumo fuchūi de, yoku mono o nakushimasu.

He is always careless and often loses things.

急きゅうな残業ざんぎょうで、友人ゆうじんとの約束やくそくに不参加ふさんかとなりました。

Kyū na zangyō de, yūjin to no yakusoku ni fusanka to narimashita.

Due to sudden overtime work, I couldn't make it to my appointment with my friend.

将来しょうらいについて不安ふあんを感かんじることは誰だれにでもあることです。

Shōrai ni tsuite fuan o kanjiru koto wa dare ni demo aru koto desu.

Feeling anxious about the future is something everyone experiences.

Related Kanji

Memory Tip

To remember the kanji 不 (fu, bu), visualize the horizontal line (一) at the top as a barrier or a ceiling. The strokes below suggest something trying to grow or move upwards but being prevented from doing so, effectively signifying 'not' or 'unable.' Imagine a plant that just 'cannot' sprout beyond a physical obstruction, or a stick figure trying to climb over a wall but 'not' succeeding. This image of being unable to pass a simple boundary helps solidify its core meaning of negation.