Intransitive vs Transitive Verbs: The Key Distinction (窓が開く vs 窓を開ける) [JLPT N4]

Content by NTJ Kuma · Nihongo to Japan editorial team · Updated August 12, 2026

A complete explanation of 「窓が開く」 vs 「窓を開ける」.

「窓が開く」 vs 「窓を開ける」 — it opens by itself vs someone opens it

「風で窓が開いた」 (the window opened in the wind) vs 「私が窓を開けた」 (I opened the window) — for the same “open,” Japanese has two verbs: intransitive (開く) = the thing changes by itself, takes 「が」; transitive (開ける) = someone does it, takes 「を」. This “intransitive/transitive” pairing is core N4 and where particles go wrong most. This guide sorts them by “who made it change” and helps you memorize the high-frequency pairs.

Core: intransitive (が, by itself) vs transitive (を, someone does)

Test: focus on “what happened to the thing” → intransitive が; on “what someone did” → transitive を.

Common intransitive/transitive pairs

Intransitive (が)Transitive (を)Meaning
開く (あく)開ける (あける)open
閉まる閉めるclose
つくつける(light) come on/turn on
消える消すdisappear/turn off
始まる始めるbegin

Examples in context

⚠️ Easy traps to avoid

① Don't mismatch particles. Intransitive takes が (窓が開く), transitive takes を (窓を開ける). English “open the window” doesn't distinguish, but Japanese matches the particle to the verb.

② You can't derive it from “add る or not.” The pairs follow no single rule (開く↔開ける, 閉まる↔閉める, つく↔つける, 消える↔消す all differ) — memorize them in pairs.

③ 「〜てある」 goes with transitive, 「〜ている」 with intransitive. 窓が開けてある (someone left it open = transitive + てある, deliberate state); 窓が開いている (it's open = intransitive + ている, plain state).

🔄 Compare with similar forms: intransitive/transitive/てある・ている

FormNuanceExample
intransitive + がthing changes/state窓が開く
transitive + をsomeone acts窓を開ける
intransitive + ている(natural) ongoing state窓が開いている (the window is open)
transitive + てあるa deliberately-made state窓が開けてある (the window has been left open by someone)

Emphasize state/result → intransitive (が); emphasize “who did it” → transitive (を); “someone set it up” → transitive + てある.

💡 The one thing to remember

Intransitive/transitive is a big N4 gate, but the mindset is simple: does the sentence stress “what the thing did by itself” or “what someone did”? — the former is intransitive + が (窓が開く), the latter transitive + を (窓を開ける). The nuisance is that the pairs follow no rule and must be memorized together (開く/開ける, つく/つける…), so learn one pair at a time with a situation. One practical point: 「電気がついている (the light is on)」 uses the intransitive and is super common. Master the dozen-plus frequent pairs and you've cleared it.

❓ Common questions

Q: How do I decide intransitive vs transitive?

By the focus and particle: stressing “the thing changed/happened” (no particular doer) → intransitive + が (ドアが開いた = the door opened); stressing “someone acted on it” → transitive + を (ドアを開けた = (I) opened the door). A clear doer with を is usually transitive.

Q: Is there a rule to derive the pairs?

No single rule. 開く/開ける, 閉まる/閉める, つく/つける, 消える/消す, 始まる/始める… all change form differently — memorize them in pairs. Group them by situation (open/close, begin, appear/disappear) and learn them with example sentences.

🖊️ Practice Questions (5)

Q1. 「風で窓___開いた。」(the window opened due to the wind — occurs by itself)

(A) が (B) を (C) に (D) で

Q2. 「私が窓___開けた。」(I opened the window)

(A) が (B) を (C) に (D) で

Q3. 「電気が___。」(the light went out — occurs by itself)

(A) 消した (B) 消えた (C) 消してある (D) 消される

Q4. 「窓が開け___」(the window is deliberately left open — an intentional state)

(A) ている (B) てある (C) ておく (D) てしまう

Q5. 自動詞の特徴として正しいのは?

(A) 動作が自然に起こる・主語は「が」(誰がしたか不問)

(B) 必ず object「を」をとる

(C) 必ず「てある」と使う

(D) 命令にしか使えない


Answer Explanations

1. (A) が ── The intransitive 「開く(あく)」takes 「が」on the subject (窓が開いた = the window opened by itself).

2. (B) を ── The transitive 「開ける」takes 「を」on the object (窓を開けた = opened the window).

3. (B) 消えた ── The intransitive 「消える」(the light went out by itself); the transitive would be 「消した」.

4. (B) てある ── 「てある」is the transitive て-form + ある = a state someone deliberately created (窓が開けてある).

5. (A) ── Intransitive = the action occurs by itself, the subject takes が, no object needed.

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