丈夫な

The Japanese word 丈夫 (じょうぶ - jōbu), usually followed by the particle な (na) when modifying nouns, is a fundamental adjective that every learner must master early in their journey. At its core, it describes something that is physically strong, durable, or resilient. However, its usage is split into two primary domains: physical objects and human health. When you talk about a 'joubu' bag, you are praising its craftsmanship and its ability to withstand heavy loads without tearing. When you describe a child as 'joubu', you are noting that they are healthy, robust, and rarely fall ill. This duality makes it a versatile tool for daily conversation.

Physical Durability

Used for furniture, clothing, tools, and structures that don't break easily. It implies a sense of reliability and long-lasting quality.

Human Vitality

Used to describe a person's constitution or body. A 'joubu na karada' (strong body) is one that resists disease and physical strain.

In terms of nuance, 丈夫 is more about 'sturdiness' than 'raw power.' While the word 強い (tsuyoi) can mean strong in a competitive or forceful sense (like a strong wrestler), 丈夫 focuses on the ability to endure. A bridge is 丈夫 because it doesn't collapse under pressure; a pair of boots is 丈夫 because the leather is thick and well-stitched. It is a highly positive word, often used when shopping or giving compliments about someone's healthy appearance. In modern Japan, you will see this word on product labels, in medical contexts, and in casual praise of well-made goods.

The word's origin is quite fascinating. The kanji 丈 (take) refers to a unit of length (about 3 meters), and 夫 (otto) refers to a man. Historically, a 'joubu' was a 'full-grown man' or a 'stately man' who was tall and physically imposing. Over centuries, the meaning shifted from the person themselves to the quality of being physically solid and dependable. Today, even a tiny, well-made clock can be called 'joubu' if it is hard to break, showing how the word has evolved from human stature to general material resilience. Whether you are at a construction site or a pediatrician's office, 'joubu' remains a go-to descriptor for anything built to last.

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Neutral to slightly formal. It is appropriate for business, shopping, and medical settings.

Using 丈夫な correctly requires understanding its grammatical classification as a na-adjective (adjectival noun). This means that when it modifies a noun directly, you must attach な (na) between the word and the noun. For example, 'a durable chair' becomes '丈夫な椅子' (jōbu na isu). If you are using it at the end of a sentence to describe a subject, you use the copula だ (da) or です (desu), such as 'この椅子は丈夫です' (kono isu wa jōbu desu). This structure is consistent across all levels of Japanese, making it a reliable pattern for learners to practice.

When negating the word, you follow the standard na-adjective rules: '丈夫ではない' (jōbu de wa nai) or '丈夫じゃありません' (jōbu ja arimasen). This is commonly used when expressing disappointment in a product that broke too easily. For instance, if a new umbrella snaps in the wind, you might sigh and say, 'この傘はあまり丈夫ではありませんね' (This umbrella isn't very sturdy, is it?). Conversely, to emphasize the degree of sturdiness, you can pair it with adverbs like とても (totemo - very), 非常に (hijō ni - extremely), or 結構 (kekkō - quite).

Noun Modification

[丈夫な] + [Noun] (e.g., 丈夫な靴 - durable shoes)

Sentence Ending

[Subject] + は + [丈夫] + です/だ (e.g., 骨は丈夫です - Bones are strong)

In more advanced contexts, 丈夫 can be used adverbially by adding に (ni). For example, '丈夫に作る' (jōbu ni tsukuru) means 'to make (something) sturdily.' This is frequently seen in manufacturing descriptions or DIY tutorials. Another common pattern is using it with the particle 'で' (de) to indicate a state: '丈夫で長持ちする' (jōbu de nagamochi suru), which translates to 'durable and long-lasting.' This specific phrase is a marketing staple in Japan, appearing on everything from kitchenware to appliances. It highlights the cultural value placed on longevity and the avoidance of waste (mottainai).

Finally, when discussing health, 'joubu' often appears in the phrase 'karada ga joubu' (the body is strong). This is a set expression. You can also use it to describe specific parts of the body, like 'ago ga joubu' (strong jaw) or 'i ga joubu' (strong stomach - meaning one can eat anything without getting sick). This anatomical focus reinforces the word's connection to physical integrity. By practicing these various patterns—noun modification, sentence endings, and adverbial use—you can accurately convey the reliability of both people and things in your Japanese environment.

You will encounter 丈夫な in a variety of everyday settings in Japan, ranging from the mundane to the professional. One of the most common places is in retail, specifically when buying items that are expected to last. If you are at a department store looking at suitcases or school bags (randoseru), the salesperson will almost certainly use 'joubu' to describe the stitching or the material. They might say, 'こちらの商品は非常に丈夫な素材を使用しております' (This product uses extremely durable materials). In this context, the word acts as a seal of quality, assuring the customer that their investment is sound.

Another frequent environment for this word is in the health and fitness world. At a gym or a doctor's office, you might hear discussions about building a 'joubu na karada' (strong body). Parents often use it when talking about their children's growth. A mother might proudly tell her friend, 'うちの子は丈夫で、一度も学校を休んだことがないの' (My child is robust and has never missed a day of school). Here, 'joubu' is synonymous with having a strong immune system and physical resilience. It is a word that carries a sense of parental pride and relief.

In the construction and engineering sectors, 'joubu' is a standard term for structural integrity. During safety briefings or architectural presentations, professionals use it to describe foundations, pillars, and joints. While they might use more technical terms like 'koukyuu' (high grade) or 'taikyuusei' (durability), 'joubu' remains the common-sense term used to explain safety to the general public. For example, after an earthquake, news reporters might interview residents who say, '家が丈夫だったので助かりました' (I was saved because the house was sturdy). This highlights the word's association with safety and protection.

In Commercials

Used to sell workwear, outdoor gear, and kitchen appliances. '丈夫で長持ち' (Sturdy and long-lasting) is a classic catchphrase.

In Schools

Teachers use it to encourage children to eat their vegetables and exercise to grow up 'joubu'.

Finally, you will hear it in casual social interactions when people discuss their physical limits. Someone might say, '私は胃が丈夫だから、辛いものを食べても大丈夫' (I have a strong stomach, so I'm fine even if I eat spicy food). Or, when lending a tool to a friend, one might say, 'これ、結構丈夫だから、乱暴に使っても壊れないよ' (This is quite sturdy, so it won't break even if you use it roughly). In all these scenarios, 'joubu' serves as a descriptor of reliability, whether it's the reliability of a human organ or a mechanical tool.

One of the most frequent mistakes English speakers make is confusing 丈夫 (jōbu) with 大丈夫 (daijōbu). While they share the same kanji characters, their meanings in modern Japanese have diverged significantly. 'Daijōbu' almost always means 'okay,' 'all right,' or 'no problem.' If someone asks if you are hurt and you say 'Joubu desu,' it sounds like you are claiming to be physically indestructible or very sturdy, rather than simply saying 'I'm okay.' Always remember: use 'Daijōbu' for 'I'm fine' and 'Joubu' for 'I am physically robust or this object is durable.'

Another common error is treating 丈夫 as an i-adjective. Because many English speakers learn words like 'hayai' (fast) or 'tsuyoi' (strong) first, they might try to say 'joubu-i' or 'joubu-kunai.' This is grammatically incorrect. As a na-adjective, its forms are 'joubu na,' 'joubu da,' and 'joubu de wa nai.' Misconjugating this word is a hallmark of beginner speech. Always double-check your adjective endings! If you are describing a 'sturdy table,' it must be 'joubu na teeburu,' never 'joubu teeburu' or 'joubu-i teeburu.'

Mistake: Confusion with 'Tsuyoi'

Learners often use 'joubu' for abstract strength. For example, 'joubu na kaze' for a strong wind. This is wrong. Use 'tsuyoi kaze.' 'Joubu' is for structural or physical resilience, not the force of nature.

Mistake: Overusing it for Health

While 'joubu' means healthy, it specifically means 'robust.' If someone is recovering from a cold, you shouldn't say 'Joubu ni natte kudasai.' Instead, use 'Odaiji ni' (take care) or 'Genki ni natte' (get well).

There is also a subtle distinction between 丈夫 (jōbu) and 頑丈 (ganjō). Beginners might use them interchangeably, but 'ganjō' is much more intense. 'Ganjō' implies something is rugged, beefy, or built like a tank. A 'joubu' box is one that doesn't break easily; a 'ganjō' box is one that you could probably drop off a building without a scratch. Using 'ganjō' for a child's health would sound a bit strange, as it's almost too 'industrial' a word for a human. Stick to 'joubu' for general health and standard durability.

Finally, avoid using 'joubu' to describe mental strength or character. In English, we might say someone has a 'sturdy character,' but in Japanese, this doesn't translate well. For mental toughness, the word 精神的に強い (seishin-teki ni tsuyoi) or 忍耐強い (nintai-zuyoi - patient/persevering) is much more natural. 'Joubu' is very much grounded in the physical world of wood, metal, bone, and muscle. By keeping your usage focused on physical integrity, you will avoid sounding unnatural to native speakers.

To truly master Japanese, you need to know not just one word, but the spectrum of words that surround it. 丈夫 (jōbu) sits in the middle of a group of adjectives describing strength and health. The most common alternative is 強い (tsuyoi). While 'tsuyoi' is a general word for 'strong' (strong wind, strong person, strong coffee), 'joubu' is specific to durability. You can have a 'tsuyoi' enemy, but you wouldn't call them 'joubu' unless you were specifically talking about how hard they are to physically damage. Understanding this boundary is key to sounding like a native.

頑丈 (Ganjō)

This word means 'rugged' or 'solidly built.' It is more intense than 'joubu.' Think of a heavy-duty safe or a massive stone wall. It emphasizes the 'heaviness' and 'unshakeable' nature of the object.

健康 (Kenkō)

While 'joubu' can mean healthy, 'kenkō' is the standard word for 'health' in a medical or lifestyle sense. 'Kenkō' refers to the state of being free from illness, whereas 'joubu' refers to the inherent strength of the body's constitution.

タフ (Tafu)

Borrowed from the English 'tough,' this is often used for mental or physical stamina, especially in sports or high-pressure jobs. It has a more modern, 'cool' nuance than the traditional 'joubu'.

In the context of materials, you might also encounter 耐久性がある (taikyūsei ga aru), which literally means 'has durability.' This is a more formal, technical phrase often found in product specifications or architectural reports. For example, a smartphone might be described as having 'taikyūsei' rather than just being 'joubu.' Another related word is 硬い (katai), which means 'hard' or 'stiff.' While a 'joubu' object might be 'katai,' the two are not the same; a rubber ball can be 'joubu' (hard to break) without being 'katai' (hard to the touch).

When describing something that is 'unbreakable,' you can use the phrase 壊れない (kowarenai). While 'joubu' is an adjective describing the quality, 'kowarenai' is a verb form describing the result. Saying 'Kono tokei wa kowarenai' (This watch doesn't break) is a more direct way of saying 'Kono tokei wa joubu da.' Finally, for things that are 'solid' or 'stable,' the word 安定している (antei shite iru) is useful, especially for structures or even financial situations. By choosing the right word from this set, you can express varying degrees of strength and reliability with precision.