減らす

The Japanese verb 減らす (herasu) is a fundamental transitive verb that translates to 'to decrease,' 'to lessen,' or 'to reduce' in English. At its core, it describes an action taken by an agent to lower the quantity, volume, size, or degree of something. Unlike its intransitive counterpart, heru (to decrease on its own), herasu implies intention or a direct cause. Whether you are cutting back on sugar, reducing your work hours, or lowering the volume on a television, herasu is the go-to term for describing the act of making something smaller in number or amount.

Grammatical Category

Godan Verb (Group 1), Transitive. It requires an object marked by the particle 'wo' (を).

Core Concept

Intentional reduction of a physical or abstract quantity. It focuses on the agent's action rather than the natural phenomenon of decline.

In daily life, Japanese speakers use 減らす in a wide variety of contexts. It is incredibly common in discussions about health and lifestyle. For instance, if a doctor advises a patient to lose weight, they might suggest reducing calorie intake or salt. In a business setting, managers often talk about reducing costs (kosuto wo herasu) or reducing the number of meetings to improve efficiency. The versatility of this word stems from its ability to handle both concrete items (like water or money) and abstract concepts (like stress or mistakes).

Furthermore, 減らす is a key vocabulary word for environmental discussions. In Japan, the '3Rs' (Reduce, Reuse, Recycle) are heavily promoted, and the 'Reduce' part is often translated or explained using 減らす. People are encouraged to reduce waste (gomi wo herasu) and reduce electricity consumption. This usage highlights the word's role in social responsibility and conscious living. It is a word that carries a sense of control and management over one's environment and habits.

When learning 減らす, it is helpful to visualize a slider or a knob being turned down. You are the one turning the knob. This mental image helps distinguish it from other words that might mean 'to cut' or 'to remove.' While kezuru might mean to shave off or cut down a budget specifically, 減らす is the broader, more general term for any kind of reduction. It is a foundational building block for expressing self-improvement, economic management, and environmental awareness in Japanese.

Synonym Comparison

Compared to sakugen suru (to cut/reduce), herasu is more common in spoken language and daily life, whereas sakugen is more formal and often used in business or government reports.

In summary, 減らす is an essential A2-level verb that empowers you to talk about changes you make to quantities. Its transitive nature makes it a proactive word, perfect for setting goals, giving advice, or explaining changes in behavior. By mastering 減らす, you gain the ability to describe how you manage your resources, your health, and your impact on the world around you.

Using 減らす (herasu) correctly requires understanding its grammatical structure as a transitive verb. The most common pattern is [Object] を 減らす. The object is the thing being reduced. Because it is a Godan verb, its conjugations follow the standard pattern: herashimasu (polite), herasanai (negative), herashita (past), and heraseba (conditional). Understanding these forms allows you to use the word in various social contexts, from casual chats with friends to formal requests.

Basic Pattern

[Noun] を 減らす (To reduce [Noun])

Target Amount Pattern

[Noun] を [Amount] に 減らす (To reduce [Noun] to [Amount])

When you want to specify the amount by which you are reducing something, or the final target amount, you use specific particles. To say 'reduce to half,' you would say hanbun ni herasu. To say 'reduce by 10%,' you might say juu-paasento herasu. This precision is vital in business and technical contexts. For example, a company might announce that they are reducing their carbon emissions by a certain percentage to meet international standards.

In the imperative or request form, 減らす is often used when giving instructions. A chef might tell an apprentice to 'reduce the heat' (hi wo yowameru is more common for heat, but ryou wo herasu for the amount of an ingredient). A teacher might tell a student to 'reduce the number of mistakes' (machigai wo herasu). In these cases, the focus is on improvement through subtraction. It is a constructive verb that points toward a more optimized or healthier state.

Another interesting use of 減らす is in the potential form, heraseru (can reduce). This is frequently used in discussions about feasibility. 'Can we reduce the costs further?' (Motto kosuto wo herasemasu ka?). This shows the word's utility in problem-solving and negotiation. It allows speakers to explore possibilities and limits of reduction in various scenarios, from personal time management to large-scale industrial processes.

Common Collocations

Weight (taijuu), Speed (sokudo), Number of people (ninzuu), Expenses (hiyou), Stress (sutoresu).

Finally, consider the causative and passive forms. Herasaseru (to make someone reduce) and herasareru (to be made to reduce). These are less common in basic conversation but appear in literature or formal reports when discussing external pressures. For example, 'The company was forced to reduce its workforce' (Kaisha wa jugyoin wo herasareta). This illustrates the full range of the verb's grammatical flexibility, making it a powerful tool for any Japanese learner.

You will encounter 減らす (herasu) in almost every corner of Japanese life, but certain environments make it particularly prominent. One of the most common places is in **commercials and advertisements**. Marketing for health foods, supplements, and 'zero-calorie' products constantly uses 減らす to promise consumers they can reduce fat, sugar, or weight. Slogans like 'Reduce your visceral fat!' (Naizou shibou wo herasu!) are ubiquitous on Japanese television and in drugstores.

Context: Health & Fitness

Used in gym settings, doctor consultations, and on food packaging to discuss lowering intake or body metrics.

Context: Workplace

Used in meetings regarding efficiency, budget cuts, and 'Work-Style Reform' (hatarakikata kaikaku) to reduce overtime.

In the **workplace**, 減らす is a keyword for efficiency. With Japan's focus on 'Work-Style Reform,' you will often hear discussions about zangyou wo herasu (reducing overtime). Managers and employees alike use this word when brainstorming ways to streamline processes. It is also the standard word used when discussing budget cuts or reducing the number of unnecessary documents (shiryou wo herasu). In these contexts, the word is associated with modernization and better management.

Another major area is **environmental awareness**. Japan has a very strict trash-sorting culture, and the goal is always to gomi wo herasu (reduce trash). You will see this on posters in apartment buildings, on city council websites, and in school classrooms. The word is tied to the concept of Mottainai (a sense of regret over waste). By reducing what we use, we show respect for resources. This cultural nuance makes 減らす a very positive, proactive word in the eyes of the public.

Finally, you'll hear it in **domestic life**. Parents tell children to 'reduce the time you spend on games' (geemu no jikan wo herashi nasai). Couples discuss how to 'reduce monthly expenses' (shuppi wo herasu) to save for a house. It is a word of practical management. Whether it's the volume of the radio or the amount of rice in a bowl, 減らす is the linguistic tool for adjustment and moderation in the Japanese household.

In summary, 減らす is not just a textbook word; it is a living part of Japanese culture that reflects the values of health, efficiency, and environmental stewardship. Hearing it in commercials, offices, and homes will give you a deep sense of how Japanese people navigate the balance of 'more' and 'less' in their daily lives.

The most frequent mistake learners make with 減らす (herasu) is confusing it with its intransitive partner, 減る (heru). This is a classic transitive/intransitive pair error. Remember: herasu requires an actor (someone doing the reducing), while heru describes something that is decreasing on its own. For example, saying 'The population reduced' using herashita would imply someone intentionally made the population smaller, which sounds quite ominous! Instead, you should use heru (decreased).

Incorrect Usage

人口を減らした (Jinkou wo herashita) - Incorrect if you mean 'The population decreased naturally.'

Correct Usage

人口が減った (Jinkou ga hetta) - Correct for natural decrease.

Another common error is using 減らす when a more specific verb like chiisaku suru (to make smaller) or yowameru (to weaken/lower) is more appropriate. While you can use herasu for volume, it technically refers to the 'amount' of sound. Most people would say oto wo chiisaku suru (make the sound smaller). Similarly, for lowering the temperature of an air conditioner, sageru (to lower) is much more natural than herasu. Using herasu for temperature sounds like you are 'reducing the amount of temperature,' which doesn't make sense in Japanese.

Learners also sometimes struggle with the particle choice. Since 減らす is transitive, it almost always takes the wo particle. However, if you are talking about the *result* of the reduction, you use ni. A common mistake is using wo for the target amount. For example, 'Reduce the price to 100 yen' should be 100-en ni herasu (or sageru), not 100-en wo herasu. The latter would mean you are taking 100 yen away from the current price, not making the final price 100 yen.

Finally, be careful with the register. While 減らす is perfectly fine for most situations, using it in a very formal business proposal might sound a bit too 'everyday.' In those cases, sakugen suru (to cut/reduce) or teigen suru (to diminish) might be expected. However, for an A2-B1 learner, herasu is usually the safest and most understood option. Just be aware that as you advance, you'll need to swap it out for more 'stiff' Kanji-based verbs in professional writing.

In conclusion, focus on the 'Who' (the agent) and the 'What' (the quantity). If you are the one doing the action, and you are dealing with a quantity or number, 減らす is likely your best friend. Avoid using it for temperature or height, and keep it distinct from the natural decline of heru, and you will sound much more like a native speaker.

While 減らす (herasu) is a versatile word, Japanese offers several alternatives depending on what exactly you are reducing and how formal you want to be. Understanding these nuances will help you choose the most natural word for the situation. The most direct synonym is 少なくする (sukunaku suru), which literally means 'to make few/little.' This is often interchangeable with herasu, but sukunaku suru feels slightly more descriptive of the resulting state, whereas herasu focuses on the action of reduction.

削減する (Sakugen suru)

A formal, technical term used for cutting budgets, emissions, or staff. It sounds professional and decisive.

削る (Kezuru)

Literally 'to shave' or 'to whittle down.' Used when you are cutting parts out of something, like a budget or a draft of a paper.

Another important alternative is 下げる (sageru), meaning 'to lower.' As mentioned in the mistakes section, sageru is used for things on a scale, like temperature, prices, or positions. You 'lower' the price (nedan wo sageru) rather than 'reducing' it with herasu, although herasu could technically be used if you're talking about the total number of costs. For physical height or abstract levels like 'quality,' sageru or otosu (to drop) are preferred.

For abstract things like 'pain' or 'burden,' you might hear 和らげる (yawarageru), which means 'to soften' or 'to ease.' If you want to say 'reduce the pain,' itami wo yawarageru is much more natural than itami wo herasu. Similarly, for 'mitigating' risks, keigen suru (to lighten/reduce) is the preferred technical term in business and law. These words provide a level of emotional or professional nuance that herasu lacks.

Finally, let's look at 縮小する (shukushou suru), which means 'to shrink' or 'to downsize.' This is used for the scale of operations or the size of an image. If a company is 'reducing its business,' they use shukushou. If they are 'reducing the number of employees,' they use herasu or sakugen. This distinction between 'size/scale' and 'number/amount' is key to advanced Japanese proficiency.

In summary, while 減らす is your primary tool for reduction, keep sakugen for formal reports, kezuru for whittling down, sageru for scales like temperature, and shukushou for downsizing. This variety allows you to be precise and expressive in your Japanese communication.