Transitive and intransitive verb pairs (他動詞・自動詞) in Japanese

In English, "open" does two jobs without changing shape. I open the door; the door opens. Same word, and nobody thinks about it. Japanese refuses this shortcut: 開ける (あける) is what a person does to a door, 開く (あく) is what a door does by itself, and they are two separate words you have to learn separately. Multiply that by a few dozen everyday actions and you have one of the most persistent sources of intermediate-level error — not because the concept is hard, but because there are so many pairs and they sound almost the same. This guide explains what the distinction does to your particles, gives you the pair table worth memorizing, shows why ている means something different on each side of a pair, and offers a drilling method that actually sticks.

1. What the distinction actually means

A transitive verb (他動詞, たどうし) describes someone acting on something. There is an agent who does it and an object it is done to. An intransitive verb (自動詞, じどうし) describes something happening to or by a subject, with no object involved and often no agent in view at all. English has this distinction too — "I ate lunch" is transitive, "I slept" is intransitive — but English mostly leaves it implicit and lets the same verb swing both ways when convenient.

Japanese marks it lexically. Where English reuses "open", "close", "start", "stop", "break", and "drop", Japanese has built morphological pairs: 開ける/開く, 閉める/閉まる, 始める/始まる, 止める/止まる, 割る/割れる, 落とす/落ちる. The two members of a pair share a kanji and an obvious family resemblance in sound, which is simultaneously a help and a trap — help because you can often guess the partner exists, trap because 閉める and 閉まる are one syllable apart and your ear will not reliably separate them for months.

Why does this matter beyond passing a grammar quiz? Because Japanese uses the choice to say something English cannot say concisely: whether the speaker is presenting an event as someone's doing or as something that happened. That is not a stylistic nicety in Japanese; it is a routine, load-bearing distinction that shows up in apologies, in business reporting, in weather forecasts, and in whether a sentence sounds like you are accepting blame. Section seven comes back to this.

2. The particle consequence: を versus が

The immediate, mechanical payoff of getting the pair right is that the particle follows automatically. A transitive verb takes a direct object marked with を. An intransitive verb has no direct object, and the thing undergoing the change is the subject, marked with が (or は when it is the topic).

• ドアを開けます。 (ドアを あけます) — "I open the door." Transitive: I am the agent, the door is the object.
• ドアが開きます。 (ドアが あきます) — "The door opens." Intransitive: the door is the subject, no agent mentioned.
• 電気を消しました。 (でんきを けしました) — "I turned off the light." 電気が消えました。 (でんきが きえました) — "The light went out."
• 会議を始めます。 (かいぎを はじめます) — "We'll start the meeting." 会議が始まります。 (かいぎが はじまります) — "The meeting starts."

This relationship runs in both directions and that is the single most useful thing about it. If you know the verb, you know the particle. If you heard the particle, you know which verb must have followed. Learners who treat particles as a separate memorization problem make this ten times harder than it is; the particle is a consequence, not an extra fact. If particles are still shaky for you generally, the particles guide covers the wider system, and the を/が split is the piece that pays off fastest here.

One caution before the table: を also marks the path or space traversed with certain intransitive motion verbs — 公園を歩く (こうえんを あるく, walk through the park), 橋を渡る (はしを わたる, cross the bridge), 家を出る (いえを でる, leave the house). Seeing を does not by itself prove a verb is transitive. This use is limited and recognizable, though, and it does not undermine the rule for the change-of-state pairs in this guide.

3. The core pair table

These are the pairs you meet first and use most. Learn them as pairs, in this order, with the readings — the readings are where the work is, since the kanji is shared and gives you nothing to distinguish them. Nearly all of these appear on the N4 list, and the JLPT tests them explicitly from N4 upward.

Two notes on the awkward rows. 終える/終わる is the textbook pair, but in everyday speech 終わる carries most of the load — 授業が終わりました (じゅぎょうが おわりました, "class ended") is far more common than anything with 終える. And 入れる/入る is the one pair whose sounds give you no help at all: いれる and はいる are not related on the surface. It has to be memorized flat.

Once the eighteen above are solid, the next tier is worth adding, and by then the patterns in the following section will make them feel almost predictable: 直す/直る (なおす/なおる, fix / be fixed), 見つける/見つかる (みつける/みつかる, find / be found), 起こす/起きる (おこす/おきる, wake someone / wake up), 並べる/並ぶ (ならべる/ならぶ, line things up / line up), 増やす/増える (ふやす/ふえる, increase something / increase), 減らす/減る (へらす/へる, reduce / decrease), 届ける/届く (とどける/とどく, deliver / arrive), 沸かす/沸く (わかす/わく, boil water / come to a boil), 冷やす/冷える (ひやす/ひえる, chill something / get cold), 汚す/汚れる (よごす/よごれる, dirty something / get dirty), 曲げる/曲がる (まげる/まがる, bend something / bend, turn). That brings the working set to about thirty pairs, which is roughly what a comfortable N3 level assumes.

4. The sound patterns — real help, but only tendencies

Scanning the table, you can see recurring shapes. They are genuinely useful for guessing and for organizing your study batches, and it would be dishonest to present them as rules, because Japanese did not design them — they are the residue of historical derivation. Treat them as strong hints.

• Ending in -す → almost always transitive. 出す, 消す, 落とす, 壊す, 直す, 増やす, 減らす, 沸かす, 汚す, 起こす. This is the most reliable pattern of the group, and it makes intuitive sense: the -す ending descends from an old causative, "make it happen".
• Ending in -aru → intransitive, with an -eru transitive partner. 閉まる/閉める, 始まる/始める, 上がる/上げる, 下がる/下げる, 集まる/集める, 決まる/決める, 止まる/止める, 変わる/変える, 見つかる/見つける, 曲がる/曲げる. Once you spot -aru, you can usually predict both the meaning and the partner.
• Ending in -reru → intransitive, often "gets damaged / comes undone". 割れる, 壊れる, 汚れる, 折れる (おれる, snap), 取れる (とれる, come off). Their partners are 割る, 壊す, 汚す, 折る, 取る.
• -eru transitive against a plain partner. 開ける/開く, 付ける/付く, 続ける/続く, 届ける/届く. Here the shorter member is the intransitive one.

Now the caveats, because relying on the patterns blindly will burn you. Not every verb has a partner at all. 走る (はしる, run), 泳ぐ (およぐ, swim) and 死ぬ (しぬ, die) are intransitive-only; 食べる (たべる, eat) and 飲む (のむ, drink) are transitive-only. Some verbs do both jobs in one form. 開く read as ひらく can be transitive or intransitive — 本を開く (ひらく, open a book) and 店が開く (ひらく, the shop opens) — while the same kanji read as あく is intransitive only. That single kanji with two readings and three behaviours is a genuine hazard, and the safest habit is to learn ドアが開く as あく and 本を開く as ひらく as two separate vocabulary items. And the endings mislead in places: 出る is intransitive despite ending in -eru, and 焼く (やく, to grill) is transitive despite the shape. Use the patterns to reduce your memorization load by maybe half; verify the other half in the dictionary.

5. Why ている means something different on each side

This is where the pairs stop being a vocabulary chore and start doing real work. The ている pattern has two readings — an action in progress, or the state resulting from a completed change — and which one you get depends on the verb. Because most intransitive members of these pairs describe an instantaneous change, they land on the state reading. Their transitive partners describe an activity, so they land on the progressive reading. Same grammar, opposite results.

• ドアが開いている。 (ドアが あいている) — "The door is open." A description of how things currently are. Nobody is doing anything.
• ドアを開けている。 (ドアを あけている) — "Someone is opening the door" (in progress), or in the right context "is keeping the door open". An action, with an agent.
• 電気がついている。 (でんきが ついている) — "The light is on." Compare 電気をつけている — "is switching the light on."
• 車が止まっている。 (くるまが とまっている) — "A car is stopped / parked there." Compare 車を止めている — "is stopping / parking the car."
• 財布が落ちている。 (さいふが おちている) — "There's a wallet lying on the ground." Not "a wallet is falling" — the falling was instantaneous and is over.

That last example is the one to keep. If you say 財布が落ちています to someone on the street, you are pointing out that they dropped their wallet and it is now on the pavement. Using the transitive 落としました would be describing the act of dropping — 財布を落としましたよ, "you dropped your wallet", which is also natural and arguably more helpful. Both work; they frame the same situation differently, and being able to choose is exactly the skill this whole topic is about. The broader mechanics of ている, including why it means "is married" for 結婚する and "knows" for 知る, are covered in the verb conjugation guide.

6. てある: the state that somebody arranged

There is a third option that only transitive verbs can take: てある. Attach it to a transitive verb and you get a resulting state, like the intransitive ている — but with the added implication that a person did it deliberately, usually as preparation. The contrast is subtle in translation and completely clear in Japanese.

• 窓が開いている。 (まどが あいている) — "The window is open." Neutral. It might have been left open, or the wind did it. No claim about why.
• 窓が開けてある。 (まどが あけてある) — "The window has been opened." Someone opened it on purpose and left it that way, probably for a reason.
• ビールが冷やしてあります。 (ビールが ひやしてあります) — "The beer has been chilled." The standard way to tell a guest that you prepared something in advance.

Note the particle: even though 開ける and 冷やす are transitive verbs that normally take を, the てある construction promotes the object to が, because the sentence is now describing the state of that thing rather than reporting an action. This surprises learners, and it is a favourite of exam writers. The related pattern ておく ("do it in advance") is the action side of the same coin: you 予約しておきます ("I'll book it ahead of time") today, and tomorrow 予約してあります ("the booking has been made"). Choosing てある when you mean "prepared" and intransitive ている when you mean "just is that way" is a small change that makes your Japanese sound considerably more precise.

7. Why Japanese reaches for the intransitive so often

Here is the pattern that surprises English speakers most. In situations where English would name a culprit or reach for the passive voice, Japanese very often just uses the intransitive verb and lets the event stand on its own.

• コップが割れました。 (コップが われました) — literally "the glass broke". English speakers instinctively produce "I broke the glass", and 私がコップを割りました is perfectly grammatical — but it foregrounds your responsibility in a way the Japanese sentence does not have to. Both exist; the intransitive is the unmarked, everyday choice.
• パソコンが壊れました。 (パソコンが こわれました) — "My computer broke." Nobody would take this as an accusation. Saying パソコンを壊しました means you broke it, and that is a confession.
• 店が閉まっています。 (みせが しまっています) — "The shop is closed." English uses a passive participle here; Japanese uses an intransitive verb in the ている state. A passive construction would be strange.
• 予定が決まりました。 (よていが きまりました) — "The schedule has been decided." Extremely common in email and at work, and notice there is no mention of who decided it. The English translation almost has to use a passive.
• お湯が沸きました。 (おゆが わきました) — "The water has boiled." You put the kettle on, but the boiling is the water's business.

It is tempting to explain this as cultural indirectness, and there is something to that, but the more practical framing is grammatical: Japanese has a rich set of intransitive verbs sitting ready for exactly this job, so it does not need the passive to express "it happened". Japanese does have a passive (the られる forms), and it uses it — but often with a flavour of being affected or inconvenienced by what someone else did: 財布を盗まれました (さいふを ぬすまれました) — "I had my wallet stolen." That adversative shading is why translating an English passive straight into a Japanese passive so often sounds wrong. The intransitive verb is usually the right target. For learners, the practical rule of thumb is simple: when the event just happened and no one needs blaming, reach for the intransitive first.

8. How to drill pairs so they stick

Standard flashcards fail on this topic, because a card reading "開ける = to open" teaches you nothing about the half of the problem that matters. Here is a method that works better, built around the fact that the difficulty is discrimination, not recall.

1. Never learn one member alone. Put both on one card, with the particle baked into the prompt: front "___ を開ける / ___ が開く", back the readings and a noun that fits. The particle is the retrieval cue you will actually have available in a real sentence.
2. Drill with a fixed sentence frame. Pick one noun and run the pair: ドアを開けます / ドアが開きます. Then swap the noun and repeat: 窓を開けます / 窓が開きます. Same pattern, new content — this is what builds the reflex rather than a fact.
3. Batch by sound pattern. Study all the -す transitives in one session, then all the -aru intransitives in the next. Grouping by shape lets the pattern do half the memorization for you, which is much more efficient than alphabetical or textbook order.
4. Always practise in the ている form too. The difference between 開いている and 開けている is where the meaning lives, and it is what listening comprehension will demand of you. Plain-form drills alone leave that gap open.
5. Narrate your own room. Walk around and describe what you see using intransitive states — 電気がついている, 窓が閉まっている, 本が落ちている — then describe what you do using transitive actions — 電気を消します, 窓を開けます. Five minutes, no materials needed, and it attaches the pairs to physical memory instead of a list.
6. Space the reviews. Confusable pairs decay faster than ordinary vocabulary, so they need more repetitions spread over more weeks. Feed them into a review deck rather than cramming; the reasoning behind the intervals is in the spaced repetition guide.

A realistic target: about twenty pairs handled confidently by the time you finish N4 material, and thirty to forty by mid-N3. That is not many words in absolute terms — the JLPT module covers 2,904 words across all five levels — but these particular forty repay the attention many times over, because they appear in almost every practical sentence about the physical world. Work them through the study tool as a dedicated set rather than letting them scatter through general vocabulary review, and check the confusable readings against the N4 vocabulary guide as you go.

9. Errors to watch for

• ×ドアを開きます. 開く is intransitive and cannot take を. It is ドアを開けます or ドアが開きます — and mixing the halves is the most common single error on this topic.
• ×会議が始めます. Same error mirrored: 始める needs an agent and an object. Use 会議が始まります for "the meeting starts".
• Mixing up 入れる and 入る. かばんに本を入れます ("I put the book in the bag") versus 部屋に入ります ("I enter the room"). Because the readings share no sound, this pair needs flat memorization more than any other.
• Using ている where てある is meant, and vice versa. 窓が開いている describes a fact; 窓が開けてある says it was set up that way. If you want the "someone prepared this" nuance, you must use the transitive verb plus てある.
• Translating English passives directly. "The door was closed" is ドアが閉まっていました, not a passive construction. Reach for the intransitive first and keep the られる passive for cases where someone was genuinely affected by another's action.
• Assuming a pair exists. Plenty of verbs have no partner. If you cannot find one in a dictionary, it probably is not there, and the workaround is the causative (〜させる) or a construction like 〜ようにする rather than an invented form.