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B1 verb #1,500 most common 9 min read

防ぐ

fusegu Top 1,500

Practice it Examples Notes & Tips 防ぐ in 30 Seconds

Explanation 防ぐ in your Level:

At the A1 level, learners are just beginning their journey into the Japanese language. The verb 防ぐ (fusegu) is generally considered too advanced for absolute beginners, who are focused on basic survival phrases, simple daily routines (eating, sleeping, going), and fundamental grammar structures like basic verb conjugations (masu-form). However, A1 learners might encounter the concept of prevention indirectly through highly common public signs or basic health advice, even if they do not actively use the verb themselves. For instance, during flu season or global health events, words related to prevention become visually ubiquitous in Japan. An A1 learner might not know how to conjugate 防ぐ, but they might recognize the kanji 防 in compound words like 予防 (yobou - prevention) on a poster at a clinic or a pharmacy. If taught at this level, it would be introduced purely as a set phrase or a vocabulary item tied to a specific, highly relevant context, such as 'washing hands to prevent a cold.' The grammatical complexity of using a transitive verb with an abstract object (like 'accident' or 'disease') is usually deferred to later stages. Teachers at the A1 level would prioritize simpler, more immediate verbs. If a student wants to express 'prevent,' they might be taught to use simpler workarounds, such as saying 'so that I don't catch a cold' (風邪をひかないように) rather than 'to prevent a cold' (風邪を防ぐために). The focus remains on building a foundation of concrete nouns and basic action verbs before moving on to the proactive, conceptual nature of 'prevention.'

As learners progress to the A2 level, their vocabulary expands to include more daily life situations, basic health, and simple problem-solving. At this stage, 防ぐ (fusegu) starts to become relevant, particularly in its dictionary form or basic masu-form (防ぎます). A2 learners are learning how to express purpose using 'tame ni' (〜ために), making this the perfect time to introduce 防ぐ in the context of everyday precautions. They can start forming sentences like 'I wear a coat to prevent the cold' (寒さを防ぐために、コートを着ます) or 'I wash my hands to prevent illness' (病気を防ぐために、手を洗います). The focus at this level is still on tangible, highly relatable concepts—weather, basic health, and simple physical safety. The distinction between 'protecting a person' (守る) and 'preventing a bad thing' (防ぐ) should be explicitly taught here to prevent the fossilization of incorrect direct translations from English. A2 learners will also start to notice the verb more frequently in their environment, such as on product packaging (e.g., 'prevents sunburn' - 日焼けを防ぐ). While they might not yet grasp the broader societal or abstract applications of the word, they can confidently use it to describe their own personal habits and the immediate reasons behind their actions. Listening comprehension exercises at this level might include simple doctor's advice or weather warnings where the word is spoken clearly and slowly, reinforcing its association with safety and well-being.

The B1 level is where 防ぐ (fusegu) truly shines and becomes an active, essential part of the learner's vocabulary. At this intermediate stage, learners are expected to discuss a wider range of topics, including news events, societal issues, workplace scenarios, and abstract concepts. 防ぐ is the perfect tool for these discussions. B1 learners will use the verb to talk about disaster prevention (災害を防ぐ), traffic safety (交通事故を防ぐ), and environmental issues (地球温暖化を防ぐ). They will master its various conjugations, particularly the potential form (防げる - can prevent) and the passive form (防がれる - is prevented). The ability to express that 'this problem can be prevented if we take action' is a key competency at the B1 level. Furthermore, learners will start integrating 防ぐ with more complex grammar structures, such as conditional clauses (もし〜すれば、ミスを防げる - if we do this, we can prevent mistakes) and nominalization (事故を防ぐことが大切です - preventing accidents is important). The vocabulary surrounding the verb also expands; instead of just 'cold' or 'cold weather,' the objects become 'global warming,' 'information leaks,' or 'economic decline.' B1 learners are also introduced to formal synonyms like 予防する (yobou suru) and 防止する (boushi suru), learning to distinguish between the native Japanese verb (wago) used in conversation and the Sino-Japanese compounds (kango) used in writing or formal speech. Mastery of 防ぐ at this level demonstrates a solid grasp of intermediate Japanese syntax and the cultural emphasis on proactive safety.

At the B2 level, learners are approaching upper-intermediate to advanced proficiency. They can understand the main ideas of complex text on both concrete and abstract topics. For a B2 learner, using 防ぐ (fusegu) is no longer just about basic grammar; it is about nuance, register, and precise communication. They will encounter the word in authentic materials such as newspaper editorials, business reports, and news broadcasts. In these contexts, 防ぐ is often part of complex, multi-clause sentences detailing strategies, policies, or technological advancements. A B2 learner can fluidly discuss corporate risk management, explaining how a new software system is designed to 'prevent unauthorized access and data breaches' (不正アクセスやデータ漏洩を防ぐ). They will also be comfortable with idiomatic or highly specific collocations, such as 未然に防ぐ (mizen ni fusegu - to nip in the bud / to prevent before it happens) or 水際で防ぐ (mizugiwa de fusegu - to stop at the border/water's edge, often used for infectious diseases or smuggling). The distinction between 防ぐ and its synonyms (防止する, 阻止する, 予防する) is fully internalized, allowing the learner to choose the exact right word based on the formality of the situation and the specific nature of the threat. In speaking and writing, a B2 learner uses 防ぐ to construct persuasive arguments, perhaps advocating for a change in local policy to 'prevent the depopulation of rural areas' (地方の過疎化を防ぐ). The verb becomes a powerful rhetorical device for discussing cause, effect, and proactive solutions.

C1 learners possess an advanced, near-fluent command of Japanese. They can express themselves fluently and spontaneously without much obvious searching for expressions. At this level, the usage of 防ぐ (fusegu) is sophisticated and deeply integrated into complex academic, professional, or literary discourse. A C1 learner does not merely use the word to state facts; they use it to analyze systemic issues, critique policies, or discuss historical events. They might read a white paper on macroeconomic policy and understand discussions about 'preventing hyperinflation' (ハイパーインフレを防ぐ) or 'preventing the collapse of the healthcare system' (医療崩壊を防ぐ). The grammatical structures surrounding the verb are highly advanced, often involving formal expressions like 〜を未然に防ぐべく (in order to prevent ~ beforehand) or 〜の蔓延を防ぐには至らなかった (did not amount to preventing the spread of ~). C1 learners also appreciate the subtle literary or emotional undertones the word can carry in different contexts. They can navigate the passive voice effortlessly, understanding complex sentences where the prevention of an event is the subject of a broader philosophical or ethical debate. Furthermore, they are adept at using the kanji 防 in its myriad compound forms, instantly recognizing and understanding highly specialized terms in fields like law, medicine, and engineering. At the C1 level, 防ぐ is a fundamental building block for articulating high-level critical thinking and engaging in nuanced debates about the future of society, technology, and global challenges.

The C2 level represents mastery and near-native proficiency. A C2 learner understands with ease virtually everything heard or read. Their use of 防ぐ (fusegu) is indistinguishable from that of an educated native speaker. At this pinnacle of language acquisition, the learner can manipulate the word across all registers, from the most casual slang to the most archaic or highly formal literary styles. They can detect the slightest nuances in tone—for example, the subtle difference in urgency or agency when a politician uses 防ぐ versus 阻止する in a heated parliamentary debate. A C2 learner can write comprehensive, publication-ready essays or reports using the word in its most abstract and complex forms, such as discussing the 'prevention of the erosion of democratic values' (民主主義的価値観の形骸化を防ぐ) or the 'prevention of cognitive dissonance in organizational behavior.' They are fully aware of the historical and cultural weight of the concept of 'defense' and 'prevention' in Japanese society, understanding how the geographical reality of Japan (prone to natural disasters) has shaped the language's extensive vocabulary around these concepts. At this level, language is not just a tool for communication, but an instrument of art and profound intellectual expression. The C2 learner uses 防ぐ with absolute precision, perfectly balancing it with complex grammar, advanced vocabulary, and deep cultural intuition to convey exact meaning in any conceivable situation.

Practice it Examples Notes & Tips

防ぐ in 30 Seconds

To prevent a bad event
To defend against an attack
To protect from weather/cold
To avert a disaster/mistake

The Japanese verb 防ぐ (fusegu) is a fundamental vocabulary word that translates primarily to 'to prevent,' 'to defend against,' or 'to protect from.' At its core, the word encapsulates the concept of anticipating a negative event, condition, or outcome and taking proactive, deliberate measures to ensure that it does not occur or to mitigate its impact if it does. The kanji used for this word is 防, which carries the intrinsic meaning of 'warding off,' 'defending,' or 'protecting.' This kanji is also found in numerous related compound words (jukugo) such as 防災 (bousai - disaster prevention), 予防 (yobou - precaution/prevention, often medical), and 防御 (bougyo - defense). When you use 防ぐ, you are implying the existence of a barrier—whether physical, conceptual, or systemic—that stops something undesirable from breaching your defenses.

Physical Prevention: This refers to stopping tangible threats, such as building a dam to prevent flooding, wearing a mask to prevent inhaling dust, or using a shield to defend against an attack.

マスクをしてウイルスの侵入を防ぐ。

Furthermore, 防ぐ is extensively used in abstract contexts. You can prevent accidents (事故を防ぐ), prevent mistakes (ミスを防ぐ), or prevent the spread of rumors (噂の拡散を防ぐ). In these cases, the 'barrier' is a set of rules, double-checks, or communication strategies.

Abstract Prevention: Implementing safety protocols in a factory to ensure that human errors do not lead to catastrophic machinery failures or workplace injuries.

パスワードを複雑にして不正アクセスを防ぐ。

The nuance of 防ぐ also extends to environmental and societal issues. For example, preventing global warming (地球温暖化を防ぐ) or preventing the decline of a local population (過疎化を防ぐ). In these macro-level contexts, the action of 'preventing' usually involves collective human effort over a long period.

Societal Prevention: Policies and educational campaigns designed to stop the progression of widespread social or environmental degradation.

リサイクルを推進して環境破壊を防ぐ。

日焼け止めを塗って紫外線を防ぐ。

シートベルトを着用して大けがを防ぐ。

Understanding the breadth of 防ぐ is crucial for mastering intermediate Japanese, as it bridges the gap between simple daily actions and complex, formal discussions about safety, health, and policy. It is a transitive verb, meaning it requires a direct object marked by the particle を (wo). You always prevent *something*. The focus is on the threat being neutralized rather than the person being protected, which distinguishes it from other similar verbs.

Using 防ぐ (fusegu) correctly requires an understanding of its grammatical properties as a Group 1 (Godan) transitive verb. Because it is transitive, it almost always takes the object particle を (wo). The structure is typically '[Negative Event/Thing] を防ぐ'. This is a fundamental rule: you do not use 防ぐ to say you are protecting a person directly (e.g., 'I prevented him' is incorrect in Japanese if you mean 'I protected him'). Instead, you prevent the *danger* that threatens the person.

Basic Transitive Usage: Use the particle を to mark the undesirable event, condition, or object that you are trying to stop from occurring or entering.

私たちは全力で敵の侵攻を防いだ。

The potential form, 防げる (fusegeru), is frequently used to express that a certain measure has the capability to stop a negative outcome. For example, 'By washing your hands, you can prevent colds' translates to 手洗いで風邪が防げる (tearai de kaze ga fusegeru). Notice that when using the potential form, the particle often changes from を to が, although を is still acceptable in modern Japanese.

Potential Form (防げる): Expresses the ability or possibility of preventing something. Often used to encourage good habits or promote safety products.

このワクチンを接種すれば、重症化を防ぐことができます。

Another vital grammatical pattern is using 防ぐ with ために (tame ni), meaning 'in order to prevent.' This is the standard way to explain the purpose of a precautionary action. 'In order to prevent traffic accidents, we installed a new traffic light' becomes 交通事故を防ぐために、新しい信号機を設置した.

Purpose Clause (〜を防ぐために): Combines the verb with 'tame ni' to state the rationale behind a specific safety measure or rule.

水漏れを防ぐために、パイプを修理した。

情報漏洩を防ぐシステムを導入する。

乾燥を防ぐクリームを顔に塗る。

Conjugation-wise, it follows standard Godan rules: Negative is 防がない (fuseganai), Past is 防いだ (fuseida), Te-form is 防いで (fuseide), and Volitional is 防ごう (fusegou). Mastering these conjugations allows you to fluidly discuss prevention in past contexts ('we prevented the crisis'), present continuous ('we are defending against the attack'), and future intentions ('let us prevent this from happening again').

The verb 防ぐ (fusegu) is ubiquitous in Japanese daily life, particularly because Japan is a country highly focused on safety, disaster preparedness, and public health. You will encounter this word constantly in news broadcasts, public announcements, product packaging, and workplace guidelines. One of the most prominent areas where 防ぐ is used is in the context of natural disasters (自然災害 - shizen saigai). Japan experiences earthquakes, typhoons, and tsunamis, so the concept of 防災 (bousai - disaster prevention) is deeply ingrained in the culture.

Disaster Preparedness: Used when discussing infrastructure, emergency kits, and evacuation drills designed to minimize damage from natural events.

土砂崩れを防ぐための工事が行われている。

Another major domain is public health and medicine. During flu season or pandemics, the phrase 感染を防ぐ (kansen o fusegu - to prevent infection) is repeated endlessly on television, posters, and government advisories. Products like masks, hand sanitizers, and air purifiers are all marketed with their ability to 'prevent' the spread of viruses.

Public Health & Medicine: Commonly paired with words like 病気 (illness), 感染 (infection), and 蔓延 (spread) to promote hygiene and vaccination.

手洗いうがいは風邪を防ぐ基本です。

In the corporate world, risk management is a critical topic. Companies hold meetings to discuss how to prevent data breaches (情報漏洩を防ぐ), prevent accounting fraud (不正を防ぐ), or prevent workplace accidents (労働災害を防ぐ). The emphasis is on creating systems that make these negative events impossible.

Business & Risk Management: Used in formal reports, incident post-mortems, and compliance training to outline preventive measures.

トラブルを未然に防ぐためのマニュアルを作成した。

サイバー攻撃を防ぐ最新のセキュリティソフト。

商品の劣化を防ぐために冷蔵庫で保管してください。

You will also see it on everyday consumer goods. Skincare products claim to prevent wrinkles (シワを防ぐ), food packaging might mention preventing oxidation (酸化を防ぐ), and gardening supplies talk about preventing weeds (雑草を防ぐ). It is a highly versatile word that spans from the most mundane daily chores to the highest levels of national security.

A frequent stumbling block for Japanese learners is distinguishing between 防ぐ (fusegu), 守る (mamoru), and 避ける (sakeru). Because English often uses 'protect,' 'prevent,' and 'avoid' in overlapping contexts, learners tend to map these English concepts directly onto Japanese verbs, leading to unnatural sentences. The most common mistake is using 防ぐ when you should use 守る.

防ぐ vs. 守る: 防ぐ takes the *threat* as its object (prevent the attack). 守る takes the *target being protected* as its object (protect the person).

❌ 家族を防ぐ。 (Incorrect: You cannot 'prevent' your family.)
✅ 家族を守る。 (Correct: Protect your family.)
✅ 家族への危険を防ぐ。 (Correct: Prevent danger to your family.)

Another common error is confusing 防ぐ with 避ける (sakeru - to avoid). While both deal with negative outcomes, the nuance of the action is entirely different. 避ける implies moving away from the threat or dodging it, without necessarily stopping the threat itself. 防ぐ implies actively putting up a barrier to stop the threat from reaching you or happening at all.

防ぐ vs. 避ける: 防ぐ is proactive and confrontational (stopping the issue). 避ける is evasive (stepping out of the way of the issue).

渋滞を避ける。 (Avoid the traffic jam - take a different route.)
渋滞を防ぐ。 (Prevent the traffic jam - build wider roads or control traffic lights.)

Learners also sometimes struggle with the conjugation, particularly confusing the transitive 防ぐ with an intransitive counterpart. Unlike some Japanese verbs that have clear transitive/intransitive pairs (like 開ける/開く), 防ぐ does not have a direct intransitive equivalent. If you want to say 'the accident was prevented,' you must use the passive form: 事故が防がれた (jiko ga fusegareta), or more naturally, rephrase it to say 'we were able to prevent the accident': 事故を防ぐことができた.

Passive Voice Usage: Remember that 防ぐ is transitive. To describe a state where prevention occurred without an active subject, use the passive 防がれる.

適切な処置により、最悪の事態は防がれた。

❌ 病気を避けるために薬を飲む。(Unnatural: You don't 'dodge' a disease with medicine.)
✅ 病気を防ぐために薬を飲む。(Correct: You prevent the disease.)

❌ 寒さを守る。(Incorrect: Protect the cold?)
✅ 寒さを防ぐ。(Correct: Defend against the cold.)

By carefully selecting the object of the verb—ensuring it is the negative element you wish to stop—you can avoid these common pitfalls and sound much more natural in your Japanese communication.

The Japanese language is rich in vocabulary related to prevention, protection, and defense. While 防ぐ (fusegu) is the most versatile and common native Japanese verb (wago) for this concept, there are several Sino-Japanese words (kango) that carry similar meanings but are used in more formal, academic, or specific contexts. Understanding these synonyms will elevate your Japanese from conversational to professional.

予防する (Yobou suru): This means 'to take precautions' or 'to prevent,' but it is heavily associated with medicine, health, and disease. You use it for vaccinations (予防接種) or preventing cavities (虫歯を予防する).

インフルエンザを予防するために、ワクチンを打つ。

Another highly formal synonym is 防止する (boushi suru). This word is composed of kanji meaning 'prevent' and 'stop.' It is used in official documents, legal contexts, and corporate policies. When a company wants to prevent a scandal from happening again, they will talk about 再発防止 (saihatsu boushi - prevention of recurrence). It sounds much stiffer and more authoritative than 防ぐ.

防止する (Boushi suru): Used in formal, administrative, or legal contexts to indicate the systematic prevention of an incident, crime, or accident.

警察は犯罪を防止するためのパトロールを強化した。

A slightly different nuance is found in 阻止する (soshi suru), which means 'to obstruct,' 'to hinder,' or 'to block.' While 防ぐ is about setting up a defense beforehand, 阻止する often implies actively intervening to stop an action that is already in progress or imminent. It has a more aggressive, confrontational tone, often used in military, sports, or political contexts.

阻止する (Soshi suru): To actively block or obstruct an opponent's action or a specific event from taking place.

野党は法案の成立を阻止しようとしている。

ゴールキーパーが相手のシュートを阻止した。

敵の侵入を未然に防ぐ。(Using fusegu for defense)

In summary, use 防ぐ as your default, everyday verb for preventing bad things. Upgrade to 予防する when talking about health and disease. Switch to 防止する when writing formal reports or discussing official policies. And use 阻止する when describing an active, forceful blocking of someone else's intentions or actions.

How Formal Is It?

Difficulty Rating

Grammar to Know

〜ために (Purpose: to prevent X, do Y)

〜ように (Purpose: so that X is prevented)

〜ないように (Negative purpose: so that X doesn't happen - often used instead of fusegu for simple things)

Potential Form (〜が防げる - X can be prevented)

Passive Voice (〜が防がれる - X is prevented)

Examples by Level

かぜをふせぎます。

I prevent a cold.

Basic masu-form. A1 learners might just memorize this as a set phrase.

これをきて、さむさをふせぎます。

I wear this to prevent the cold.

Using te-form to connect actions.

マスクでかぜをふせぐ。

Prevent colds with a mask.

Using particle で for means/method.

てをあらって、びょうきをふせぎましょう。

Let's wash our hands and prevent illness.

Volitional form (mashou) for suggestion.

あめをふせぐかさです。

It is an umbrella that prevents rain.

Verb modifying a noun (relative clause).

じこをふせぐために、とまります。

I stop in order to prevent an accident.

Basic 'tame ni' (in order to) structure.

むしをふせぐくすりです。

It is medicine to prevent bugs (bug spray).

Simple noun modification.

どうやってふせぎますか？

How do you prevent it?

Question word 'douyatte' (how).

病気を防ぐために、毎日野菜を食べます。

I eat vegetables every day to prevent illness.

Using ために (tame ni) for purpose.

日焼けを防ぐクリームを買いました。

I bought cream to prevent sunburn.

Modifying a noun (クリーム) with a verb phrase.

窓を閉めて、虫が入るのを防ぎます。

I close the window to prevent bugs from entering.

Nominalizing a verb phrase with の (no).

シートベルトはけがを防ぐことができます。

Seatbelts can prevent injuries.

Using ことができる (koto ga dekiru) for potential.

手洗いはウイルスを防ぐのに役立ちます。

Hand washing is useful for preventing viruses.

Using のに役立つ (no ni yakudatsu) - useful for.

事故を防ぐために、ゆっくり運転してください。

Please drive slowly to prevent accidents.

Combining ために with a request (てください).

この服は寒さを防げます。

These clothes can prevent the cold.

Potential form 防げる (fusegeru).

火事を防ぐために、火を消しました。

I put out the fire to prevent a fire (disaster).

Past tense action for prevention.

地球温暖化を防ぐために、私たちは何ができるでしょうか。

What can we do to prevent global warming?

Using formal societal topics (地球温暖化).

パスワードを定期的に変更して、不正アクセスを防ぎましょう。

Let's change our passwords regularly to prevent unauthorized access.

IT/Business vocabulary integration.

トラブルを未然に防ぐことが、マネージャーの重要な役割です。

Preventing trouble before it happens is an important role of a manager.

Common collocation: 未然に防ぐ (mizen ni fusegu).

このシステムを導入すれば、情報漏洩は防げるはずだ。

If we introduce this system, we should be able to prevent information leaks.

Conditional ば (ba) and expectation はず (hazu).

ワクチンの普及により、感染の拡大が防がれた。

Thanks to the spread of the vaccine, the expansion of the infection was prevented.

Passive voice 防がれる (fusegareru).

過労死を防ぐための新しい法律が施行されました。

A new law to prevent death from overwork has been enacted.

Complex noun modification with ための (tame no).

ミスを防ぐには、ダブルチェックが欠かせません。

To prevent mistakes, double-checking is indispensable.

Using には (ni wa) for 'in order to'.

ダムの建設は、洪水を防ぐ目的で行われました。

The construction of the dam was carried out for the purpose of preventing floods.

Using 目的 (mokuteki - purpose).

サイバー攻撃を水際で防ぐための高度なセキュリティ対策が求められている。

Advanced security measures are required to prevent cyber attacks at the border.

Advanced collocation: 水際で防ぐ (mizugiwa de fusegu).

少子高齢化による労働力不足を防ぐ施策が急務である。

Measures to prevent labor shortages due to the declining birthrate and aging population are an urgent task.

Academic/News vocabulary (少子高齢化, 施策, 急務).

品質の劣化を防ぐべく、特殊な包装技術が採用されている。

In order to prevent quality deterioration, special packaging technology is employed.

Formal grammar: べく (beku - in order to).

過去の教訓を活かし、悲劇の再発を未然に防がなければならない。

We must utilize the lessons of the past and prevent the recurrence of the tragedy before it happens.

Strong obligation: なければならない (nakereba naranai).

インフレの進行を防ぐために、中央銀行は金利の引き上げを決定した。

To prevent the progression of inflation, the central bank decided to raise interest rates.

Economic context and terminology.

その法律は、大企業による市場の独占を防ぐ役割を果たしている。

That law plays a role in preventing the monopolization of the market by large corporations.

Using 役割を果たす (yakuwari o hatasu - play a role).

建物の倒壊を防ぐには、耐震補強工事が不可欠だ。

To prevent the collapse of the building, seismic reinforcement work is essential.

Technical vocabulary (倒壊, 耐震補強).

ストレスによるメンタルヘルスの悪化を防ぐ取り組みが企業に広がっている。

Initiatives to prevent the deterioration of mental health due to stress are spreading among companies.

Complex subject phrase modifying 取り組み (torikumi - initiative).

パンデミックの蔓延を完全に防ぐには至らなかったが、被害は最小限に抑えられた。

Although it did not amount to completely preventing the spread of the pandemic, the damage was kept to a minimum.

Advanced grammar: には至らなかった (ni wa itaranakatta - did not reach the point of).

権力の腐敗を防ぐための三権分立というシステムは、民主主義の根幹を成す。

The system of the separation of powers to prevent the corruption of authority forms the foundation of democracy.

Political science terminology (権力の腐敗, 三権分立).

歴史の改竄を防ぐことは、後世に対する我々の重大な責務である。

Preventing the falsification of history is our grave responsibility to future generations.

Highly formal vocabulary (改竄, 後世, 責務).

生態系の崩壊を未然に防ぐべく、国際社会が協調して対策を講じる必要がある。

The international community needs to take coordinated measures in order to prevent the collapse of the ecosystem before it happens.

Formal literary style (べく, 対策を講じる).

市場の暴落を防ぐためのセーフガードが発動され、取引は一時停止となった。

Safeguards to prevent a market crash were triggered, and trading was temporarily suspended.

Financial jargon (暴落, セーフガード, 発動).

その条約は、核兵器の拡散を防ぐという崇高な理念に基づいて締結された。

The treaty was concluded based on the noble ideal of preventing the proliferation of nuclear weapons.

Diplomatic language (拡散, 崇高な理念, 締結).

言語の消滅を防ぐためのアーカイブ化プロジェクトが、言語学者たちによって進められている。

An archiving project to prevent the extinction of languages is being advanced by linguists.

Academic context (消滅, アーカイブ化).

アルゴリズムの偏りがもたらす差別の再生産を防ぐための倫理的ガイドラインが急務だ。

Ethical guidelines are urgently needed to prevent the reproduction of discrimination brought about by algorithmic bias.

Tech ethics vocabulary (偏り, 差別の再生産).

如何なる巧妙な詭弁をもってしても、その政策がもたらす破綻を防ぐことは叶わなかった。

No matter what clever sophistry was used, it was impossible to prevent the collapse brought about by that policy.

Highly literary and dramatic phrasing (如何なる〜をもってしても, 叶わなかった).

文明の退行を防ぐという命題は、単なる技術的課題ではなく、哲学的な問いである。

The proposition of preventing the regression of civilization is not merely a technical challenge, but a philosophical question.

Philosophical discourse (退行, 命題).

国家の介入による表現の自由の侵害を水際で防ぐ砦として、司法の独立性が問われている。

The independence of the judiciary is being questioned as a fortress to prevent the infringement of freedom of expression by state intervention at the very edge.

Complex metaphorical usage (砦として, 水際で防ぐ).

その微細な亀裂が致命的な構造欠陥へと発展するのを防ぐには、熟練工の直感に頼るほかなかった。

To prevent that microscopic crack from developing into a fatal structural defect, there was no choice but to rely on the intuition of a skilled worker.

Technical narrative style (致命的, 発展するのを防ぐ).

グローバル資本主義の暴走を防ぐための新たなパラダイムシフトが、今まさに希求されている。

A new paradigm shift to prevent the runaway of global capitalism is exactly what is being sought right now.

Academic/Sociological terminology (暴走, パラダイムシフト, 希求).

記憶の風化を防ぎ、惨禍を語り継ぐことこそが、生き残った者の背負うべき十字架である。

Preventing the weathering of memory and passing down the story of the disaster is precisely the cross that survivors must bear.

Poetic and emotional literary style (風化, 惨禍, 十字架).

細胞の老化を根本的に防ぐメカニズムの解明は、生命科学における究極の聖杯と言えよう。

The elucidation of the mechanism that fundamentally prevents cellular aging can be said to be the ultimate holy grail in life sciences.

Scientific/Academic rhetoric (根本的に, 聖杯と言えよう).

情報の非対称性が引き起こす市場の失敗を未然に防ぐための制度設計が、経済学者の腕の見せ所だ。

Institutional design to prevent market failures caused by information asymmetry before they happen is where economists show their skill.

Advanced economic theory (情報の非対称性, 市場の失敗, 制度設計).

Common Collocations

事故を防ぐ

感染を防ぐ

ミスを防ぐ

被害を防ぐ

トラブルを防ぐ

悪化を防ぐ

再発を防ぐ

未然に防ぐ

水際で防ぐ

寒さを防ぐ

Common Phrases

〜を未然に防ぐ

〜の再発を防ぐ

〜を防ぐために

〜を水際で防ぐ

〜が防がれる

〜を防ぐことができる

〜の侵入を防ぐ

〜の拡大を防ぐ

〜の悪化を防ぐ

〜を最小限に防ぐ

Often Confused With

防ぐ vs 守る (mamoru - to protect): You protect the *good* thing (person, country). You prevent the *bad* thing (accident, attack).

防ぐ vs 避ける (sakeru - to avoid): Avoiding means you dodge the problem. Preventing means you stop the problem from happening at all.

防ぐ vs かばう (kabau - to cover for/protect): Used when physically shielding someone or taking the blame for them. Not used for abstract prevention.

Idioms & Expressions

"未然に防ぐ (nip in the bud)"

"水際で防ぐ (stop at the border)"

"先手を打って防ぐ (preemptively prevent)"

"防戦一方 (entirely on the defensive - related concept)"

"転ばぬ先の杖 (a cane before you fall - proverb related to prevention)"

"備えあれば憂いなし (if you are prepared, you don't have to worry - proverb)"

"火の粉を払う (brush off sparks - ward off danger)"

"未曾有の事態を防ぐ (prevent an unprecedented situation)"

"波及を防ぐ (prevent the ripple effect)"

"被害を食い止める (stem the damage - similar usage)"

Easily Confused

防ぐ vs

Sentence Patterns

How to Use It

nuance

Implies a proactive, deliberate action to stop a specific threat. It is not used for passively avoiding something by just walking away (that is 避ける - sakeru).

formality

Neutral. Can be used in casual conversation and formal news. However, for highly official documents, Sino-Japanese equivalents like 防止 (boushi) are preferred.

Common Mistakes

Using 防ぐ with a positive object (e.g., ❌子供を防ぐ instead of ✅子供を守る).
Confusing 防ぐ (prevent) with 避ける (avoid). You prevent an accident (事故を防ぐ), but you avoid a person you dislike (嫌な人を避ける).
Trying to use it intransitively. You cannot say ❌事故が防いだ. You must use the passive ✅事故が防がれた or the potential ✅事故が防げた.
Using it to stop a person from doing a specific daily action. ❌彼が帰るのを防ぐ. ✅彼が帰るのを止める (tomeru).
Confusing the pronunciation with 塞ぐ (fusagu - to plug/block). They sound similar but have different kanji and primary meanings.

Tips

Always check your object

Before writing a sentence with 防ぐ, ask yourself: 'Is the object a bad thing?' If it's a good thing, change the verb to 守る (mamoru).

Upgrade your business Japanese

In a business meeting, instead of saying 'ミスを防ぐ' (prevent mistakes), try saying 'ミスの再発を防止する' (prevent the recurrence of mistakes). It sounds much more professional.

Memorize '未然に'

The adverb 未然に (mizen ni) is the best friend of 防ぐ. Using them together (未然に防ぐ) immediately makes your Japanese sound natural and fluent.

Flat pitch accent

Pronounce ふせぐ with a flat (heiban) pitch. Do not put a heavy accent on the 'fu'. It should sound smooth and level.

Proactive vs Reactive

Remember that 防ぐ is proactive. You do it *before* the disaster strikes. If the disaster is already happening and you are trying to stop it, verbs like 食い止める (kuitomeru - to stem/halt) are better.

The 'Mound' Radical

The kanji 防 has the 'mound/hill' radical (阝) on the left. Think of it as building a hill of dirt to stop a flood. This visual helps remember the meaning.

News Keywords

When watching Japanese news, if you hear 'bousai' (防災), 'yobou' (予防), or 'boushi' (防止), you know the topic is about preventing something bad. Listen for the specific threat.

Potential form particle shift

When you change 防ぐ to the potential form 防げる, the object particle を often changes to が. '事故を防ぐ' becomes '事故が防げる'.

Don't use for people's actions

Don't use 防ぐ to say 'I prevented him from eating the cake.' Use 止める (tomeru - to stop) instead: '彼がケーキを食べるのを止めた'.

Use with ために

The most common sentence structure you will write is '[Bad Thing] を防ぐために、[Action] をする'. Master this template for essays and tests.

Memorize It

Mnemonic

Imagine a FUSE (ふせ) that is cut to prevent (防ぐ - gu) a bomb from exploding. You cut the FUSE to GUard against the explosion.

Word Origin

Native Japanese word (wago). The kanji 防 (bou/fuse-gu) originally depicts a mound or wall (the left radical 阝 means hill/mound) and a direction/square (方), symbolizing a physical barrier erected in a specific direction to ward off enemies or floods.

Cultural Context

Disaster prevention. September 1st is 'Disaster Prevention Day' (防災の日) in Japan, commemorating the 1923 Great Kanto Earthquake. Schools and companies hold drills to practice how to 'prevent' casualties.

Preventive medicine. The Japanese healthcare system places a heavy emphasis on annual health checks (健康診断) to 'prevent' serious illnesses before they develop.

Practice in Real Life

Real-World Contexts

Conversation Starters

"最近、風邪を防ぐために何か特別なことをしていますか？ (Are you doing anything special to prevent colds lately?)"

"日本は地震が多いですが、家でどんな災害を防ぐ対策をしていますか？ (Japan has many earthquakes; what disaster prevention measures do you take at home?)"

"仕事でミスを防ぐために、どんな工夫をしていますか？ (What kind of tricks do you use to prevent mistakes at work?)"

"地球温暖化を防ぐために、個人でできることは何だと思いますか？ (What do you think individuals can do to prevent global warming?)"

"ストレスを防ぐ一番の方法は何ですか？ (What is the best way to prevent stress?)"

Journal Prompts

Write about a time you successfully prevented a big mistake or accident.

List three things you do every day to prevent illness or maintain your health.

Discuss a global issue (like climate change) and what measures should be taken to prevent it from getting worse.

How does your country approach disaster prevention compared to Japan?

Write a short guide on how to prevent cyberbullying or online scams.

Frequently Asked Questions

10 questions

No, you cannot translate the English structure 'prevent [person] from [action]' directly using 防ぐ. In Japanese, you would use a causative-negative structure or verbs like 止める (tomeru - to stop). For example, '彼が帰るのを止めた' (I stopped him from going home). 防ぐ is used for preventing negative events, not people's general actions.

防ぐ is a broad, native Japanese verb used for preventing any kind of negative event (accidents, leaks, cold weather). 予防する (yobou suru) is a Sino-Japanese word heavily restricted to health, medicine, and disease. You use 予防 for vaccines and preventing cavities, but you wouldn't use it for preventing a traffic accident.

Because 防ぐ means to prevent or defend against a *threat*. If you say '家族を防ぐ', it sounds like your family is the enemy or the disaster that you are trying to stop from happening. You must use 守る (mamoru - to protect) for things you want to keep safe: 家族を守る.

The most common way to say 'preventive measures' is 防ぐための対策 (fusegu tame no taisaku) or simply 予防策 (yobousaku) in medical contexts, and 防止策 (boushisaku) in business or formal contexts.

It is strictly a transitive verb. It requires a direct object marked by the particle を (wo). You must always prevent *something*. There is no direct intransitive equivalent; if you need an intransitive meaning, you must use the passive form 防がれる (fusegareru - to be prevented).

Yes, absolutely. While it can be used for physical things like preventing water from leaking, it is very commonly used for abstract concepts like preventing mistakes (ミスを防ぐ), preventing inflation (インフレを防ぐ), or preventing global warming (温暖化を防ぐ).

未然に防ぐ (mizen ni fusegu) is a very common set phrase that means 'to prevent something before it happens' or 'to nip it in the bud.' 未然 means 'before it becomes a reality.' It emphasizes the proactive nature of the prevention.

Since it is a Group 1 (Godan) verb ending in 'gu', you drop the 'u' and add 'eru', making it 防げる (fusegeru). This means 'can prevent' or 'is preventable.' For example, 'この病気は薬で防げる' (This disease can be prevented with medicine).

The direct stem noun form is 防ぎ (fusegi), but it is rarely used on its own in modern Japanese. Instead, you will see it in compound nouns like 防ぎよう (fusegiyou - method of prevention, usually used in the negative: 防ぎようがない - there is no way to prevent it) or Sino-Japanese nouns like 予防 (yobou) and 防止 (boushi).

Yes, you can use it for the *effects* of weather. You can say 寒さを防ぐ (prevent the cold from reaching you) or 雨を防ぐ (shield against the rain). However, you cannot prevent the weather itself from happening (you can't say 雨が降るのを防ぐ unless you have a weather-control machine; you would say 雨を避ける - avoid the rain).

Test Yourself 200 questions

writing

Translate: 'I wear a mask to prevent a cold.'

Well written! Good try! Check the sample answer below.

Use 風邪を防ぐ (prevent a cold) + ために (in order to) + マスクをします (wear a mask).