Skip to content
JLPT N3Expressions

をもとに(して)— Based On

Indicates the source, material, or foundation on which something is created, judged, or done — 'based on', 'on the basis of', or 'using ... as a basis'. It marks the reference material that serves as the starting point. The form をもとにした modifies a following noun.

Grammar path · 練習

Practice this in the path

A short lesson: the pattern, its sentence anatomy, a quick quiz and a sentence to build.

Pro lessonUNIT 103 · EXPRESSIONS

Structure · 形

[Noun] + をもとに(して) ／ [Noun] + をもとにした + [Noun]

Examples · 例文

  • この映画は実話をもとに作られた。

    Kono eiga wa jitsuwa o moto ni tsukurareta.

    This film was made based on a true story.

    実話 (true story) + をもとに marks the source material of the film.

  • アンケートの結果をもとにして、商品を改良した。

    Ankeeto no kekka o moto ni shite, shouhin o kairyou shita.

    We improved the product based on the survey results.

    結果 (results) + をもとにして shows the basis for the improvement.

  • 彼の体験をもとにした小説がベストセラーになった。

    Kare no taiken o moto ni shita shousetsu ga besutoseraa ni natta.

    A novel based on his experiences became a bestseller.

    をもとにした modifies 小説 to mean 'a novel founded on his experiences'.

Usage notes · 注意

  • Marks the raw material or reference that something is built upon.
  • をもとにした／をもとにする modifies a noun.
  • Register: neutral to formal; common with creating, judging, or revising.

Commonly confused with

The JLPT rarely asks whether you recognise a pattern — it asks which of several similar patterns fits. These are the ones をもとに(して) is tested against.

vsに基づいて

に基づいて (based on rules/principles) implies strict conformity to a standard, while をもとに treats the source as raw material that may be freely adapted.

vsを中心に

を中心に means an activity revolves around a focal point, whereas をもとに marks the material or source that something is built from.

More expressions

Study Japanese grammar on LenGaki

Everything on this page, ready to study

  • 7,788 JLPT vocabulary words, N5 through N1, with readings and audio (N5 free)
  • 2,057 kanji with on'yomi, kun'yomi and stroke-order practice
  • 445 grammar points with examples and commonly-confused comparisons
  • Full-length N5 and N4 mock exams, timed, with real listening audio (N5 sets 1 and 2 free)