〜をもとに: 'Based On / Using X as a Basis'
Using something as the foundation for something new
〜をもとに marks the material — data, an experience, a story — that gets reworked into a new creation.
この映画は実話をもとに作られた。
この えいがは じつわを もとに つくられた。
This movie was made based on a true story.
The true story is raw material; the film can dramatize and invent freely.
やったんは自分の失敗談をもとに、新しい絵本を作った。
やったんは じぶんの しっぱいだんを もとに、あたらしい えほんを つくった。
Yattan made a new picture book based on his own story of failure.
A personal experience becomes the seed for a new work.
Form
〜をもとに attaches directly to a noun describing the source material, and is often followed by して before the main verb.
| Attaches to | Pattern | Example |
|---|---|---|
| Noun | Noun + をもとに(して) + Verb | アンケート結果をもとに開発した |
お客様の声をもとに、新製品を開発した。
おきゃくさまの こえを もとに、しんせいひんを かいはつした。
We developed a new product based on customer feedback.
をもとにして is equally natural here.
Nuance: をもとに vs に基づいて
〜に基づいて ("based on / in accordance with") is the more formal, stricter cousin — used for laws, official data, and rules that must be followed precisely (法律に基づいて判断する). 〜をもとに is looser: the source inspires or supplies material, but the result can freely reinterpret it (実話をもとにした映画).
The short version
- 〜をもとに = "based on / using X as a basis (that gets reworked)"
- Attaches to: Noun + をもとに(して) + Verb
- Nuance/register: source material can be freely adapted; common in creative and everyday contexts
- Don't confuse with: に基づいて (stricter, for laws/official data that must be followed precisely)
Practice it
Choose をもとに to mark the source material something new was built from.
＿＿＿に入れるのに最もよいものを選びなさい。
この映画は＿＿＿作られた。
Where 〜をもとに fits
Shaky on this? Get these solid first
- を · N5 — を marks the direct object of a verb (パンを食べる), the path you move along (道を歩く), and the place you leave (家を出る). Learn all three uses with examples.
More N2 grammar to explore
Keep going with related patterns at the same level:
- 〜を除いて — 〜を除いて means 'except for / excluding X,' carving one item out of a group before describing the rest; often strengthened to 〜を除いては when contrasting the exception more sharply against everything else.
- やがて — やがて is an adverb meaning 'soon,' 'before long,' or 'eventually' — something will happen after a stretch of time passes. Common in narration and storytelling to bridge from one scene to a later, changed one.
- 〜やら〜やら — 〜やら〜やら lists two or more things (or feelings) side by side to convey a chaotic, overwhelming, or mixed situation — 'what with A and B.' Casual-to-neutral, and often used for jumbled emotions.
- 〜ようでは — 〜ようでは means 'if (this) is the state of things' — a current situation, if it continues, will lead to a bad result. Used to criticize or warn, often followed by a negative conclusion.
- 要するに — 要するに is a conjunction meaning 'in short' or 'the point is' — it introduces a summary or rephrasing of what was just said, boiling a longer explanation down to its essence.
- 〜に向かって — 〜に向かって attaches to a noun and means 'toward / facing,' marking physical motion toward a place, effort aimed at a goal, or words directed at a person: 駅に向かって走る ('run toward the station').