Meaning & Usage
The grammar pattern 「～をもとに」 (o moto ni) is used when creating, developing, or conceptualizing something new, taking an existing source, data, or experience as its fundamental basis. It translates most accurately to phrases like "based on," "drawing upon," "using X as a foundation," or "inspired by." This pattern emphasizes that the noun preceding をもとに isn't just a mere reference; it's a crucial, foundational element from which something new originates or is built.
Think of 「～をもとに」 as building something new (Y) upon an existing foundation (X). The foundation (X) is indispensable for the creation of Y. For instance, a movie might be 「実話をもとにした映画」 (a movie based on a true story), or a report could be 「調査結果をもとに作成された」 (prepared based on research results). In both cases, the original "true story" or "research results" are not simply mentioned but actively form the core from which the movie or report takes shape.
This grammar point implies that the source material undergoes a process of interpretation, analysis, or adaptation. It's often used in contexts of creative works (novels, films, designs), academic research, business planning, and data analysis. While you might use 「～から」 (kara) to simply state a source (e.g., "made from wood"), 「～をもとに」 conveys a deeper connection. It signifies that the source material serves as the conceptual or informational basis for something more complex or developed.
The nuance of 「～をもとに」 is generally formal and objective. It's very common in written Japanese, academic papers, news reports, business documents, and formal presentations. While not unheard of in spoken language, it sounds more structured and less casual than simpler expressions. It conveys a sense of credibility and thoroughness, indicating that the subsequent creation or decision isn't arbitrary but grounded in concrete information or experience.
Structure & Formation
The formation of 「～をもとに」 is straightforward:
- Noun + をもとに
- Noun + をもとに ＋ Verb (often followed by a verb of creation or development)
- Noun + をもとにした ＋ Noun (used to modify another noun, describing it as "based on X")
The particle 「を」 marks the noun as the direct object being utilized as the foundation. Optionally, 「にして」 can be added after 「をもとに」 (e.g., 「をもとにして」) to form a conjunctive phrase, often implying a slightly more active process of "making X the base." Both forms are correct and often interchangeable, with 「をもとに」 being slightly more concise.
| Type | Pattern | Example | Meaning |
|---|---|---|---|
| Basic Form | Noun + をもとに | データをもとに | Based on data |
| Verb Phrase | Noun + をもとに + V | 経験をもとに開発する | Develop based on experience |
| Adjectival Phrase | Noun + をもとにした + Noun | 事実をもとにした小説 | A novel based on facts |
It can attach to various types of nouns, including abstract concepts like 「経験」 (experience), 「データ」 (data), 「情報」 (information), 「事実」 (facts), and 「物語」 (story).
Example Sentences
Creative Works
この映画は、人気の漫画をもとに作られました。
Kono eiga wa, ninki no manga o moto ni tsukuraremashita.
This movie was made based on a popular manga.
彼の小説は、実際に起こった事件を非常にリアルにもとにしている。
Kare no shōsetsu wa, jissai ni okotta jiken o hijō ni riaru ni moto ni shiteiru.
His novel is very realistically based on an actual incident that occurred.
この新しい製品のデザインは、自然界の美しさを大きくもとにしています。
Kono atarashī seihin no dezain wa, shizenkai no utsukushisa o ōkiku moto ni shiteimasu.
The design of this new product is largely based on the beauty of the natural world.
Research & Analysis
調査結果を厳密にもとに、今後の方針を決定します。
Chōsa kekka o genmitsu ni moto ni, kongo no hōshin o kettei shimasu.
We will decide on future policies strictly based on the research results.
その論文は、過去の研究データをもとに新しい仮説を立てています。
Sono ronbun wa, kako no kenkyū dēta o moto ni atarashī kasetsu o tateteimasu.
That paper is establishing a new hypothesis based on past research data.
顧客からのフィードバックをもとにして、サービスを改善しました。
Kokyaku kara no fīdobakku o moto ni shite, sābisu o kaizen shimashita.
We improved the service based on customer feedback.
Planning & Development
市場調査をもとに、新しいマーケティングプランを作成しました。
Shijō chōsa o moto ni, atarashī māketingu puran o sakusei shimashita.
We created a new marketing plan based on market research.
地域住民の意見をもとに、公園の設計が見直された。
Chiiki jūmin no iken o moto ni, kōen no sekkei ga minaosareta.
The park design was revised based on the opinions of local residents.
これらのデータをもとに、次の戦略を立てましょう。
Korera no dēta o moto ni, tsugi no senryaku o tatemashō.
Let's formulate our next strategy based on this data.
Personal Experiences / Information
私の経験をもとにして、彼にアドバイスをしました。
Watashi no keiken o moto ni shite, kare ni adobaisu o shimashita.
I gave him advice based on my experience.
子どもの成長記録書は、毎月の検診データをもとに作成される。
Kodomo no seichō kirokusho wa, maitsuki no kenshin dēta o moto ni sakusei sareru.
The child's growth record is created based on monthly health check-up data.
顧客アンケートをもとに、新しいメニューを開発しました。
Kokyaku ankēto o moto ni, atarashī menyū o kaihatsu shimashita.
We developed a new menu based on customer questionnaires.
聞いた情報をもとにして、自分なりに判断した。
Kiita jōhō o moto ni shite, jibun nari ni handan shita.
I made my own judgment based on the information I heard.
その建築家は、地元の伝統をもとにしたデザインを提案した。
Sono kenchikuka wa, jimoto no dentō o moto ni shita dezain o teian shita.
The architect proposed a design based on local traditions.
収集した資料をもとにして、歴史レポートを書いた。
Shūshū shita shiryō o moto ni shite, rekishi repōto o kaita.
I wrote a history report based on the collected materials.
Common Mistakes
Mistake 1: Using for simple reference without creation/development
「～をもとに」 implies that something new is created or developed from the source. It's not typically used for simply "referring to" or "talking about" something.
❌ 私は、辞書をもとに、単語の意味を調べた。
✅ 私は、辞書で単語の意味を調べた。
The incorrect sentence implies creating a new meaning based on the dictionary, which isn't the case. You're just looking up an existing meaning. For simple reference, use 「で」 (de) or 「を参考にして」 (o sankō ni shite).
Mistake 2: Confusing with simple "from" sources (～から)
While 「～から」 can indicate a source, 「～をもとに」 specifies that the source is a foundation for a new creation or decision, often involving analysis or interpretation.
❌ 木をもとに作られたテーブル。
✅ 木から作られたテーブル。
Wood is a raw material, not usually an informational or conceptual "basis" for a table. For raw materials, 「～から」 is more appropriate. 「をもとに」 works best with abstract nouns, data, stories, etc., where intellectual or creative work is done upon the source.
Mistake 3: Using in overly casual conversation
「～をもとに」 carries a somewhat formal tone. While understandable, it might sound a bit stiff in very casual, everyday conversations where simpler phrases might be more natural.
❌ 「きのうのドラマ、実話をもとに作られてたんだって！」 ✅ 「きのうのドラマ、実話がもとになってたんだって！」 or 「きのうのドラマ、実話がベースだったんだって！」
While the incorrect sentence is grammatically sound, the correct examples use slightly more common or relaxed expressions for casual speech, especially 「～がもとになっている」 or borrowing the English "based."
Mistake 4: Incorrect particle usage
Always use the particle 「を」 before 「もとに」. Other particles like 「に」 or 「で」 are incorrect in this specific pattern.
❌ 経験にもとにアドバイスする。
✅ 経験をもとにアドバイスする。
「経験」 is the direct object being utilized as a foundation, hence 「を」 is required.
Cultural Notes
In Japanese business, academia, and media, the use of 「～をもとに」 is highly valued. It signifies diligence and credibility, showing that a proposal, report, or creative work isn't arbitrary but grounded in verifiable facts, thorough research, or authentic experiences. This meticulousness in citing sources and acknowledging foundations speaks to a broader cultural emphasis on precision and accountability.
When encountered in news articles describing films, books, or documentaries, this phrase often sets an expectation for realism or authenticity, as the work claims to be derived from real events or established facts. Similarly, in business presentations or academic papers, stating that a conclusion or plan is 「データをもとに」 (based on data) lends significant weight and persuades the audience of its soundness.
It also subtly communicates a process of transformation: the original material isn't simply reproduced but undergoes interpretation, analysis, or artistic rendering to become something new. This transformative aspect is a key part of its meaning and cultural utility.
JLPT Tips
When studying 「～をもとに」 for the JLPT N3, focus on its core meaning: "using X as a foundation to create or develop Y." This means you should look for contexts where something new or a decision is being formed, with the preceding noun serving as the crucial source material. Pay attention to the verb that follows 「をもとに」; it will often be a verb of creation, analysis, planning, or decision-making (e.g., 作る, 開発する, 計画する, 判断する, 決定する).
Practice distinguishing 「をもとに」 from similar grammar points like 「～に基づいて」 and 「～を参考にして」. Remember that 「をもとに」 emphasizes the fundamental basis for creation. In contrast, 「に基づいて」 often implies adherence to rules or principles, and 「を参考にして」 suggests using something as a helpful reference. If the sentence implies a direct, foundational relationship where the source material is indispensable for the outcome, then 「をもとに」 is likely the correct choice.
Also, keep in mind its somewhat formal register. While it might appear in a listening section, it's more prevalent in reading comprehension questions dealing with reports, articles, or official statements. Recognizing the Noun + をもとに (して) structure is key. It's also important to understand that the noun before を marks the foundational source.