をもとに

をもとに means based on. It is a JLPT N2 Japanese grammar pattern used to say something is created or judged from a source or foundation.

This grammar point often appears in advanced reading, formal writing, notices, essays, and careful conversation. If you want to read Japanese with more nuance, をもとに is a useful pattern to learn because it shows the speaker’s logic, stance, or emphasis.

What does をもとに mean?

Use をもとに when you want to say something is created or judged from a source or foundation.

Natural translations include:

• based on
• depending on context
• in a way that matches the speaker’s emphasis

The best translation depends on the sentence. Focus first on what relationship the pattern creates between the ideas.

How to form をもとに

Noun + をもとに

Examples of the pattern:

• 実話をもとにした映画です。
• アンケート結果をもとに
• 昔話をもとに

In JLPT questions, pay close attention to the word immediately before the grammar point. Many wrong answers use a similar meaning but attach to the wrong form.

When is をもとに used?

Use をもとに in situations like:

• reading formal explanations, announcements, or essays
• making a point more precise than a basic grammar pattern would
• connecting two ideas with a clear nuance

Tone and register:

• usually neutral to formal, depending on the expression
• common in JLPT N2 reading passages, news, notices, and business-like writing

をもとに example sentences

• 実話をもとにした映画です。 — It is a movie based on a true story.
• アンケート結果をもとに、商品を改善した。 — We improved the product based on survey results.
• 昔話をもとに、新しい物語を書いた。 — I wrote a new story based on an old tale.
• データをもとに、今後の方針を決める。 — We will decide the future policy based on data.
• この資料をもとに、発表の準備をしてください。 — Please prepare your presentation based on this material.

After reading each sentence, ask what job をもとに is doing. Is it adding, excluding, warning, emphasizing, or showing a condition? That habit makes the nuance easier to remember than a single English translation.

Nuance of をもとに

The key nuance is say something is created or judged from a source or foundation.

This matters because N2 grammar often overlaps with easier expressions. The advanced pattern usually adds formality, emphasis, restriction, or a stronger logical relationship.

For example:

• In formal writing, をもとに often sounds more precise than a casual equivalent.
• Compared with に基づいて, it has a different tone or scope even when the English translation looks similar.

をもとに vs に基づいて

Both をもとに and に基づいて can express related ideas, but they are different.

をもとに:

• fits the N2 nuance explained above
• often sounds more specific, formal, or emphatic

に基づいて:

• is usually broader, simpler, or used in a different register
• may be better in casual conversation depending on the sentence

Quick contrast examples:

• 実話をもとにした映画です。
• Try rewriting the sentence with に基づいて and notice whether the tone or meaning changes.

Common mistakes with をもとに

Watch out for these mistakes:

• Translating it too literally and missing the function in context
• Confusing it with に基づいて just because the English translation overlaps
• Using it in casual speech when a simpler pattern would sound more natural

A helpful practice method is to write one sentence with をもとに, then compare it with a related grammar point. Explain the difference in your own words.

Is をもとに on the JLPT?

Yes. をもとに is commonly taught as JLPT N2 grammar.

That means learners should be able to:

• recognize it in reading
• understand its nuance in context
• use it in simple original sentences

For test preparation, study the grammar point in full sentences. JLPT questions usually test context, not dictionary translation alone.

Practice questions for をもとに

Try making your own sentences with these prompts:

• Write one sentence that clearly needs をもとに.
• Write a second sentence with に基づいて and compare the nuance.
• Find a notice, article, or dialogue where this kind of meaning would be natural.

Learning path for をもとに

To learn をもとに efficiently, follow a path that matches this pattern’s real function.

1. First review the formation so the base structure feels natural.
2. Then compare をもとに with に基づいて and the related lessons below. These recommendations are chosen from similar semantic or structural families.
3. Finally, write your own sentence where the context makes をもとに necessary.

Related grammar to review next

• n2 ni motozuite — review this next because it is close in meaning, form, or register
• n2 no ue de wa — review this next because it is close in meaning, form, or register
• n3 ni yotte — review this next because it is close in meaning, form, or register

Learn をもとに with Hane

If you want to review をもとに together with the related patterns above, Hane helps you connect grammar, kanji, and vocabulary in short, focused sessions.

Browse more lessons here:

• All grammar lessons
• JLPT N2 grammar lessons