“〜ni motozuite・ni motozuku”: Based On / In Accordance With 〜 (a written grounding) [JLPT N2]

Content by NTJ Kuma · Nihongo to Japan editorial team · Updated July 27, 2026

Master 〜に基づいて to take your Japanese up a level!

「データに基づいて、結論を出す」 — grounded in facts, not on a hunch

Writing a report, 「憶測ではなく、データに基づいて判断すべきだ」 (one should judge based on data, not on guesswork) — 「〜に基づいて・〜に基づく」 = based on ～, on the basis of ～, meaning “grounding oneself in ～ (some basis, standard) to judge or act.” What precedes is mostly law, data, facts, rules — “things that serve as a basis.” It's a formal, written expression. This guide covers its use, the attributive 「に基づく,」 and how to tell it from 「をもとに」「に沿って.」

Core: grounding in some basis/standard to act

「noun ＋ に基づいて／に基づき」 means “grounding oneself in ～ (a basis, standard, principle), to judge/act accordingly”:

• 事実に基づいて、報道する (report based on facts).
• 法律に基づき、処理する (handle it in accordance with the law).
• アンケート結果に基づく分析 (analysis based on survey results).

Feel: “based on ～, on the basis of ～” — the core is “taking ～ as the ‘basis, standard' for judgment/action, proceeding accordingly.” What precedes is mostly 法律・データ・事実・規則・経験・原則 — “things serving as a basis,” and what follows is “the judgment/action made on that basis.” It carries the formal sense of “grounded, following a standard,” mostly for writing (official documents, reports, news). To modify a noun, use the attributive 「に基づく ＋ noun.」

Forms & attachment

Examples in use

• 憶測ではなく、事実に基づいて議論しよう。(Let's argue based on facts, not guesswork.)
• この作品は、実際の事件に基づいて書かれた。(This work was written based on a real incident.)
• 会社の規則に基づき、彼は処分を受けた。(In accordance with company rules, he was disciplined.)
• 長年の経験に基づくアドバイスは、説得力がある。(Advice based on years of experience is persuasive.)
• 科学的な根拠に基づいた主張が求められる。(Claims based on scientific grounds are called for.)

⚠️ Easy traps to avoid

① What precedes is ‘法律・データ・事実・規則' etc. — ‘things that serve as a basis.' The first clause of 「に基づいて」 is mostly things that can serve as the ‘basis, standard, ground' for judgment/action — 法律・規則・契約・データ・事実・証拠・経験・原則・方針・調査結果. It means “taking this as the ground, judging/acting accordingly,” with the sense of “grounded, following a standard”: 事実に基づいて (based on facts), 法律に基づき (in accordance with the law), データに基づく (based on data). So what precedes is “a standard/ground to follow.” Test: is the preceding “a thing serving as a basis/standard (law/data/facts/rules…)”? Yes → に基づいて applies. It stresses “not out of thin air, not on a hunch, but with this basis.”

② Formal, written; attributive uses 「に基づく.」 「に基づいて／に基づき」 has a clear formal, written color, mostly for official documents, reports, news, academic settings, expressing “grounded, following a standard.” It's rare in everyday speech (which uses 「〜をもとに」 or plainly 「〜を見て」「〜に従って」). Also, to modify a noun, use the attributive 「に基づく」 (not 「に基づいて」): ○ データに基づく判断 (a judgment based on data — modifies the noun 「判断」), ○ 事実に基づいた報道 / × データに基づいて判断 (when modifying a noun, use に基づく／に基づいた). Test: attach 「に基づいて」 to a verb clause; 「に基づく／に基づいた」 to a noun.

③ 「に基づいて」 vs 「をもとに」 vs 「に沿って」: judge by a standard vs make from material vs follow a policy. These three all mean “based on/following ～,” but with different emphases. 「〜に基づいて」 = based on ～ (grounding in a standard/basis to judge/act): stresses “following a standard, a ground” (law・data・facts): 事実に基づいて判断する (judge based on facts). 「〜をもとに（して）」 = based on ～, from ～ (using something as material/model to make/create): stresses “using something as a model, material, to make/create something new”: 実話をもとにした映画 (a film based on a true story), この資料をもとに発表する (present based on this material). 「〜に沿って」 = along/following ～ (following a set policy, process, line): stresses “going along a policy/process/route”: 計画に沿って進める (proceed along the plan), マニュアルに沿って操作する (operate following the manual). Difference: 「に基づいて」 is grounding judgment in a standard/basis (法律に基づく); 「をもとに」 is making from a material/model (実話をもとに); 「に沿って」 is going along a policy/process (計画に沿って). Test: to judge/act by a standard use に基づいて; to make/create from material use をもとに; to follow a policy/process use に沿って.

🔄 Compare: に基づいて／によって／をもとに／に沿って

💡 Learning tip

「〜に基づいて・に基づく」 = based on ～, on the basis of ～ (grounding judgment/action in a standard/basis) — three points: ① precedes ‘法律・データ・事実・規則' etc. — things serving as a basis — 事実に基づいて (based on facts), 法律に基づき (in accordance with the law), stressing “grounded, not on a hunch”; ② formal/written, attributive uses 「に基づく」 — to modify a noun use に基づく (データに基づく分析), for a verb clause use に基づいて; rare in everyday speech; ③ separate it from relatives — 「をもとに」 is making from material/model (実話をもとに), 「に沿って」 is following a policy/process (計画に沿って), 「に基づいて」 is judging by a standard/basis (法律に基づく). This pattern suits stressing “grounded” in reports and argument — 「〜に基づいて判断/分析」 makes it sound objective, grounded, professional in one line.

❓ Questions you might have

Q: 「に基づいて」 and 「をもとに」 both mean ‘based on ～, on the basis of ～' — what's the difference?

The difference is “grounding judgment in a standard/basis” vs “making from a material/model.” 「〜に基づいて」 = based on ～ (grounding oneself in a standard/basis, to judge/act accordingly): precedes 法律・データ・事実・規則・原則 — “standards serving as a basis for judgment/action,” stressing “following this standard, with this ground” to judge or act: 事実に基づいて判断する (judge based on facts), 法律に基づいて処理する (handle in accordance with the law), 証拠に基づいて結論を出す (draw a conclusion based on evidence). Its focus is “taking ～ as the ‘ground for judgment/action'” (grounded). 「〜をもとに（して）」 = based on ～, from ～ (using something as a model/material to make/create something new): precedes 素材、資料、故事、経験 — “things serving as a model/material,” stressing “using this as material/model to make something new”: 実話をもとにした小説 (a novel based on a true story), このデータをもとにグラフを作る (make a graph from this data), 彼の証言をもとに捜査を進める (advance the investigation from his testimony as a lead). Its focus is “taking ～ as ‘material/model for making/creating.'” Difference: 「に基づいて」 is “following a standard/basis to ‘judge/act'” (法律に基づいて判断); 「をもとに」 is “using material/a model to ‘make/create'” (実話をもとに小説を書く). Test: to say “judge/act by some standard/basis” (law, data, facts) → に基づいて; to say “make/create from some material/model” (a story, materials, experience as a model) → をもとに. E.g. 「アンケート結果に基づいて、方針を決める (decide a policy based on survey results — judge by a standard)」 uses に基づいて; 「アンケート結果をもとに、レポートを書く (write a report from survey results as material — make from material)」 uses をもとに. Sometimes the two are close and interchangeable, but 「に基づいて」 leans “judging by a standard,” 「をもとに」 leans “making from material.”

Q: How do I use 「に基づいて」 and 「に基づく」? What's the difference?

The difference is what follows: for a verb clause (adverbial) use 「に基づいて／に基づき,」 for a noun (attributive) use 「に基づく／に基づいた.」 「〜に基づいて／に基づき」 is adverbial, modifying the following verb/clause: 事実に基づいて判断する (judge based on facts — modifies 「判断する」), 法律に基づき処理する (handle in accordance with the law — modifies 「処理する」). What follows is a verb/clause. 「〜に基づく／に基づいた」 is attributive, modifying the following noun: データに基づく分析 (analysis based on data — modifies the noun 「分析」), 事実に基づいた報道 (reporting based on facts — modifies the noun 「報道」), 経験に基づくアドバイス (advice based on experience). What follows is a noun. The test is dead simple: see whether a verb or a noun follows 「に基づいて／に基づく」 — a verb/clause (判断する, 処理する) → に基づいて／に基づき; a noun (分析, 報道, 判断, アドバイス) → に基づく／に基づいた. This is just Japanese's general rule of “連用 (て) modifies verbs, 連体 (る/た) modifies nouns.” E.g. 「規則に基づいて処分する (discipline in accordance with the rules — modifies the verb)」 uses に基づいて; 「規則に基づく処分 (discipline in accordance with the rules — modifies the noun)」 uses に基づく. Remember “modify a verb → に基づいて, modify a noun → に基づく” and you won't slip. 「に基づき」 is the written abbreviation of 「に基づいて」 (more formal).

🖊️ Practice Questions (5)

Q1. 「国際法___、この行為は違法だ。」(Under international law, this act is illegal)

(A) に基づいて　(B) について　(C) に対して　(D) によって

Q2. 「アンケートの結果___、商品デザインを改善した。」(improved the product design based on the survey results)

(A) に従って　(B) に基づいて　(C) について　(D) に反して

Q3. 「証拠___判断を下した。」(made a judgment based on the evidence; attributive form)

(A) に基づいて　(B) に基づく　(C) に基づき　(D) に従い

Q4. 「先生の指示___行動してください。」(act according to the teacher's instructions) — which is most natural?

(A) に基づいて　(B) に従って　(C) に対して　(D) について

Q5. 「科学的データ___分析された結果を報告します。」(the results analyzed based on scientific data); attributive form

(A) に基づく　(B) に基づいて　(C) に基づき　(D) に従う

Answer Explanations

1. (A) に基づいて ── 「国際法 (standard) に基づいて (based on/according to)」→ に基づいて.

2. (B) に基づいて ── 「アンケート結果 (data/basis) に基づいて改善 (acting on it)」→ に基づいて.

3. (B) に基づく ── 「証拠に基づく判断 (modifying the noun 「判断」)」needs the attributive form → に基づく. (A) に基づいて / (C) に基づき are conjunctive forms (connecting to verbs) and can't directly modify a noun; (D) に従い has a different meaning.

4. (B) に従って ── 「先生の指示に従って (act following the instructions)」→ に従って emphasizes "obeying/following instructions." に基づいて means "based on a standard," better suited to legal/data contexts.

5. (A) に基づく ── 「科学的データに基づく分析 (attributive, modifying 分析)」→ に基づく (attributive form modifying the following noun 「分析」).