〜とされる

The Japanese expression 〜とされる is a highly versatile and frequently used grammatical structure that translates roughly to 'it is considered that', 'it is believed that', or 'it is said to be' in English. To truly grasp the nuance of this expression, one must first break down its components. It is derived from the quotation particle 'と' (to) combined with 'される' (sareru), which is the passive form of the irregular verb 'する' (suru, meaning 'to do' or 'to make'). When someone says 'AをBとする' (A o B to suru), they are actively deciding, assuming, or treating A as B. Therefore, when this is shifted into the passive voice as 'AはBとされる' (A wa B to sareru), the active agent—the person doing the considering or assuming—is removed from the spotlight. The focus shifts entirely to the widely accepted state, belief, or consensus regarding the subject. This makes it an incredibly objective and detached way to present information, which is exactly why it is so prevalent in formal contexts such as news broadcasts, academic papers, historical documentaries, and official reports. You will rarely hear this used in casual, everyday conversations among friends about trivial matters, as it carries a weight of authority and general consensus. Instead of expressing a personal opinion, the speaker uses this structure to distance themselves from the claim, attributing it to a collective understanding or an unnamed group of experts. For instance, if a scientist discovers a new health benefit of a certain food, a news anchor might report it using this structure to indicate that the scientific community now holds this belief, rather than the news anchor stating it as their own personal conviction.

Objective Stance

By using the passive voice, the speaker completely removes their own subjectivity. It signals to the listener that the information being presented is not a mere personal thought, but a fact that is recognized by a broader community, society, or specific field of study.

Formal Register

This grammar point belongs strictly to the formal and written registers of the Japanese language. It is a staple of 'kaki-kotoba' (written language) and formal 'hanashi-kotoba' (spoken language) used in professional presentations, journalism, and academia.

Nuance of Consensus

Unlike 'と言われる' (to iwareru), which simply means 'it is said' and can refer to rumors or casual hearsay, this expression implies a stronger sense of considered judgment, evaluation, or established consensus among people who have thought about the matter.

When learning this structure, it is crucial to pay attention to the context in which it appears. You will often find it paired with words related to history, science, statistics, and societal norms. For example, when discussing the origins of a cultural festival, a historian might explain that the festival 'is believed to have started in the Edo period'. In Japanese, this would perfectly align with the use of this grammar point, as it represents a historical consensus rather than an absolute, undeniable fact witnessed by the speaker. It leaves a tiny margin of possibility that new evidence could change this consensus, which is a very scientifically and academically honest way to present information. This subtle hedging is a hallmark of polite and professional Japanese communication, where making overly assertive claims without acknowledging the collective understanding can sometimes be viewed as arrogant or unrefined.

Furthermore, the expression can be conjugated just like any other passive verb. You might see it in the past tense as 'とされた' (was considered), in the negative as 'とされない' (is not considered), or in the te-form as 'とされており' (is considered, and...). This flexibility allows writers and speakers to weave complex, multi-layered sentences that clearly establish the background knowledge or accepted facts before introducing new arguments or contrasting information. Understanding this grammar point is an absolute necessity for anyone aiming to read Japanese newspapers, comprehend news broadcasts, or engage with any material that goes beyond daily, casual conversation. It is a gateway to the sophisticated, objective world of adult Japanese discourse.

Constructing sentences with this grammar point requires a solid understanding of how to connect different parts of speech to the quotation particle 'と' (to). Because 'と' is used to quote or frame a statement, the word or phrase immediately preceding it must generally be in the plain or short form. This is a fundamental rule of Japanese grammar that applies to many similar structures, such as 'と思う' (to omou, I think) or 'と言う' (to iu, to say). However, there are specific nuances depending on whether you are connecting a verb, an i-adjective, a na-adjective, or a noun. Let us explore each of these connections in exhaustive detail to ensure you can use this structure flawlessly in your own writing and formal speaking. When connecting a verb, you simply use the dictionary form, the plain past form (ta-form), or the plain negative form (nai-form). For example, if you want to say 'It is believed that eating vegetables is good', you would take the verb '食べる' (taberu, to eat) or the state '良い' (yoi, good) and attach the grammar point directly. If the sentence ends in a verb, such as 'The population will decrease', you take '減少する' (genshou suru) and add the grammar point to make '減少するとされる' (genshou suru to sareru). This direct connection makes verbs relatively straightforward to handle.

Verbs

Attach directly to the plain form of the verb. Example: 降る (furu, to fall) becomes 降るとされる (furu to sareru, it is believed it will fall).

I-Adjectives

Attach directly to the plain form of the i-adjective. Example: 難しい (muzukashii, difficult) becomes 難しいとされる (muzukashii to sareru, it is considered difficult).

Nouns and Na-Adjectives

This is where learners often make mistakes. You must include the copula 'だ' (da) or the more formal 'である' (de aru) before the quotation particle. Example: 問題 (mondai, problem) becomes 問題だとされる (mondai da to sareru) or 問題であるとされる (mondai de aru to sareru).

The inclusion of 'だ' (da) or 'である' (de aru) for nouns and na-adjectives is a critical point of focus. If you omit the copula and simply say '問題とされる' (mondai to sareru), it is technically grammatically acceptable in some very specific, older, or highly condensed literary contexts, but in modern standard Japanese, especially in clear academic or journalistic writing, '問題だとされる' or '問題であるとされる' is the expected and correct form. The form 'である' (de aru) elevates the formality of the sentence significantly, making it perfectly suited for academic dissertations or official government white papers. When you are writing an essay for a Japanese proficiency test, such as the JLPT N2 or N1, using 'であるとされる' will demonstrate a high level of grammatical command and an understanding of appropriate register. Another important structural consideration is the use of the continuous state. As mentioned previously, 'とされている' (to sarete iru) is frequently used instead of just 'とされる'. The distinction is subtle but important. 'とされる' states a general, timeless fact or a future assumption, while 'とされている' emphasizes that this is the current, ongoing consensus held by people right now. In most news reports discussing current beliefs or ongoing scientific consensus, you will hear the 'te iru' form.

Let us also look at how to modify nouns using this structure. If you want to say 'a disease that is considered incurable', you must use the structure as a relative clause modifying the noun 'disease'. The phrase '不治の病だとされる' (fuji no yamai da to sareru, considered an incurable disease) directly precedes the noun it modifies. So, '不治の病だとされる病気' (fuji no yamai da to sareru byouki) translates to 'a disease that is considered to be an incurable disease'. This ability to embed complex assumptions and beliefs into noun phrases is incredibly powerful for constructing advanced, descriptive sentences. It allows writers to pack a dense amount of contextual information into a single sentence without needing to break it up into multiple simpler sentences. Mastering this relative clause usage is a major milestone in transitioning from intermediate to advanced Japanese proficiency.

If you are studying Japanese purely through casual conversation with friends, watching slice-of-life anime, or reading lighthearted manga, you might go months without ever encountering this grammar point. However, the moment you step into the realm of adult, professional, or academic Japanese, it will appear with overwhelming frequency. This expression is the absolute backbone of objective reporting and formal exposition in Japan. The most common place you will hear this is on television news broadcasts, particularly on networks like NHK. When a news anchor is reporting on a criminal investigation, a political development, or a natural disaster, they are bound by strict journalistic standards to remain objective. They cannot say 'I think the suspect fled in a car' or 'Everyone says the economy will get worse'. Instead, they must rely on the consensus of authorities, experts, or the police. Therefore, you will constantly hear phrases like '容疑者は海外へ逃亡したとされる' (yougisha wa kaigai e toubou shita to sareru, the suspect is believed to have fled overseas) or '経済は回復に向かうとされている' (keizai wa kaifuku ni mukau to sarete iru, the economy is considered to be heading towards recovery). This linguistic distancing protects the network from making unfounded claims while still delivering the most current theories and beliefs to the public.

News Broadcasts

Used constantly by anchors and reporters to state facts based on police reports, government announcements, or expert analysis without injecting personal bias.

Academic Papers

Essential for literature reviews and establishing the current state of research. Scholars use it to summarize what is generally accepted in their field before introducing their own novel research.

Documentaries

Narrators in historical or scientific documentaries use this to describe theories about the past or phenomena that cannot be proven with absolute certainty but are widely accepted by experts.

Beyond the news, academic writing is another major domain for this grammar point. If you ever read a Japanese university dissertation, a scientific journal article, or even a high-level textbook, you will see this structure used to establish the baseline of human knowledge on a topic. In academia, stating something as an absolute fact is often frowned upon unless it is an immutable law of nature. Most knowledge is treated as the current best understanding, subject to future revision. Therefore, a historian writing about the Sengoku period will not write 'Oda Nobunaga did this for this exact reason', but rather 'It is considered that his motivation was...'. This shows intellectual humility and respect for the academic process. Furthermore, in the corporate world, business reports, market analyses, and official company statements frequently employ this structure. When a company predicts future market trends, they will frame it as 'The market is expected/considered to grow' to avoid making a legally binding promise while still providing a professional forecast based on data. Understanding this context is vital for anyone looking to work in a Japanese corporate environment or consume Japanese media intended for educated adults.

Finally, you will also encounter this in legal documents, government white papers, and official guidelines. In these highly formalized texts, precision and objectivity are paramount. A government health guideline might state that 'A daily intake of this vitamin is considered necessary for maintaining health'. The use of the passive voice here creates a sense of authoritative distance. It is not just one doctor's opinion; it is the official stance of the health ministry based on collective medical consensus. For learners of Japanese, immersing yourself in these types of materials—reading news articles on NHK Web Easy, watching documentaries on YouTube in Japanese, or reading introductory academic texts—is the best way to internalize the natural rhythm and context of this essential grammatical structure. It elevates your comprehension from merely understanding the literal words to grasping the subtle social and professional dynamics at play in Japanese communication.

When learners first encounter this grammar point, they often struggle with its appropriate usage, leading to several common and predictable mistakes. The most frequent error is using this highly formal, objective structure to express personal, subjective opinions. Because it translates to 'it is considered', a learner might mistakenly think they can use it to say 'I consider this movie to be boring' by saying 'この映画はつまらないとされる' (kono eiga wa tsumaranai to sareru). This sounds incredibly unnatural and almost comical to a native speaker. It sounds as if the learner is declaring that the entire world, or a panel of esteemed experts, has reached a formal consensus that the movie is boring. For personal opinions, one must use 'と思う' (to omou, I think) or 'と感じる' (to kanjiru, I feel). This grammar point is strictly reserved for general consensus, objective facts, or beliefs held by a collective group, not an individual's personal taste or fleeting thought. Understanding this boundary between the subjective 'I' and the objective 'society/experts' is crucial for mastering advanced Japanese expression.

Mistake: Personal Opinions

Using it for subjective feelings. Incorrect: 私はこのケーキが美味しいとされる。 Correct: 私はこのケーキが美味しいと思う。

Mistake: Missing Copula

Forgetting 'だ' or 'である' after nouns and na-adjectives. Incorrect: それは問題とされる。 Correct: それは問題だとされる。

Mistake: Overuse in Casual Speech

Using it in daily conversation with friends. It sounds overly stiff and academic. In casual speech, use 'って言われてる' (tte iwareteru) or 'らしい' (rashii) instead.

Another very common grammatical mistake involves the connection rules, specifically regarding nouns and na-adjectives. As emphasized in the usage section, you must insert the copula 'だ' (da) or 'である' (de aru) before the quotation particle 'と'. Many learners, accustomed to structures that attach directly to nouns, will simply write 'Noun + とされる'. While this might be understood, it is grammatically flawed in modern standard writing and will be marked incorrect on language proficiency exams. For instance, instead of writing '原因はウイルスだとされる' (the cause is considered to be a virus), a learner might write '原因はウイルスとされる'. The omission of 'だ' breaks the logical grammatical link required by the quotation particle. Always remember that 'と' needs a complete thought or state to quote, and for a noun, that state is established by the copula. Furthermore, learners sometimes confuse this grammar point with the causative-passive form. The verb 'する' (to do) becomes 'させる' (to make someone do) in the causative, and 'させられる' (to be made to do) in the causative-passive. 'とされる' is simply the passive form of 'とする' (to assume/consider). Mixing these up can lead to completely nonsensical sentences.

Lastly, a subtle but important mistake is ignoring the nuance of certainty. This grammar point implies a high degree of acceptance and consensus, but it is not an absolute, undeniable truth like 'The sun rises in the east'. It is used for theories, historical beliefs, and scientific consensus that, while highly trusted, still contain a microscopic margin of doubt inherent in the scientific method or historical analysis. If you use this grammar point to state an obvious, unchangeable, and universally experienced fact, it can sound strange. For example, saying '水は冷たいとされる' (Water is considered to be cold) sounds bizarre because the coldness of water (in a specific context) is a direct sensory experience, not a theoretical consensus reached by experts. It is better used for things that require investigation, analysis, or collective agreement, such as 'その地域の水はミネラルが豊富だとされる' (The water in that region is considered to be rich in minerals). Refining your sense of when a fact requires 'consensus' versus when it is just a simple reality is a key step in mastering advanced Japanese nuance.

The Japanese language is rich with expressions used to convey hearsay, consensus, and objective beliefs. Navigating the subtle differences between these similar words is a hallmark of advanced proficiency. The most immediate relative to our target grammar point is 'と言われている' (to iwarete iru), which translates to 'it is said that'. While they are often interchangeable in broad contexts, 'と言われている' focuses more on the act of people speaking or a general rumor spreading. It feels slightly less formal and less academic. For example, '納豆は体に良いと言われている' (It is said that natto is good for you) implies that this is common knowledge passed around by people. On the other hand, '納豆は体に良いとされている' (Natto is considered good for you) implies that medical professionals or scientific studies have established this as a recognized fact. The former is based on widespread talk; the latter is based on evaluation and consensus. Another close alternative is 'と考えられている' (to kangaerarete iru), meaning 'it is thought that'. This is extremely similar in formality and usage to our target grammar point, but it explicitly highlights the process of logical thought or deduction by experts. You will often see 'と考えられている' in scientific papers discussing hypotheses.

と言われている (to iwarete iru)

Meaning: It is said that. Focuses on spoken rumors, folklore, or general public chatter. Less formal and less authoritative than the target grammar point.

と考えられている (to kangaerarete iru)

Meaning: It is thought that. Highly formal. Focuses on the logical deduction and active thinking process of experts or scholars.

らしい (rashii) / そうだ (sou da)

Meaning: It seems that / I heard that. These are much more casual and are used in everyday conversation to relay information heard from a specific source or based on observation.

When deciding which expression to use, consider the source of the information and the tone of your writing. If you are writing a casual blog post about a local urban legend, 'と言われている' or even 'らしい' is perfectly appropriate. However, if you are translating a formal business report detailing market expectations, 'とされている' or 'と見られている' (to mirarete iru, it is viewed that) are the correct choices. 'と見られている' is another excellent alternative frequently used in journalism and economics. It implies that observers, analysts, or the public are currently viewing a situation in a certain way. For example, '来年は景気が回復すると見られている' (It is viewed that the economy will recover next year). This carries a nuance of observation and prediction based on current trends. Understanding this spectrum of expressions—from the casual 'らしい' to the rumor-based 'と言われている', to the thought-based 'と考えられている', to the observation-based 'と見られている', and finally to the consensus-based 'とされている'—gives you immense precision in expressing exactly how a piece of information is known and regarded in Japanese society.

In conclusion, while 'とされる' is a powerful tool for formal communication, it is not the only tool in the box. By mastering its alternatives, you avoid sounding repetitive in long essays or presentations. A skilled Japanese writer will seamlessly weave between 'とされている', 'と考えられている', and 'と言われている' depending on the specific nuance they wish to convey in each sentence. This variety not only makes the writing more engaging but also demonstrates a profound, native-like command of the language's subtle epistemic markers—the grammatical ways a language indicates how we know what we know. Keep practicing these distinctions, and your formal Japanese will become incredibly sophisticated and precise.