Two Japanese sentences can both come out in English as "the window is open," yet they say different things. 窓が開いている is a bare observation. 窓が開けてある hints at a person: someone opened it on purpose and left it that way. This page is the quick-decision guide — how to pick 〜ている or 〜てある in the moment. It does not re-teach the transitivity machinery underneath; for the full paradigm, the verb-pair lists, and the deeper "agent hiding" analysis, see 〜ている vs 〜てある: intransitive vs transitive result. Here you get a flowchart you can run in a second.
Two questions settle it
| Step | Question | Result |
|---|---|---|
| 1 | Is your verb intransitive (自動詞: 開く, つく, 落ちる) or transitive (他動詞: 開ける, つける, 落とす)? | Intransitive → ている (forced). Transitive → go to step 2. |
| 2 | Are you describing a resulting state someone set up, or an action happening right now? | Resulting state → てある (が). Action in progress → ている (を). |
The first question does most of the work, because the verb you reach for forces the auxiliary: an intransitive verb can only take ている, and てある only attaches to a transitive verb. You are not free to swap them.
Question 1: intransitive or transitive?
Japanese pairs most change-of-state verbs — one that "happens by itself" (自動詞) and one where "someone does it" (他動詞). The one you choose dictates the auxiliary automatically.
- Intransitive verb → ている: reports a neutral state, no one credited.
- Transitive verb → てある: reports a state that a person deliberately produced.
道に財布が落ちている。
michi ni saifu ga ochite iru
There's a wallet lying on the road. (intransitive 落ちる — just the state, nobody blamed)
玄関に大きな荷物が置いてある。
genkan ni ōkina nimotsu ga oite aru
A big parcel has been set down in the entryway. (transitive 置く — someone put it there on purpose)
出発の3時間前だけど、もう空港に着いている。
shuppatsu no san-jikan mae da kedo, mō kūkō ni tsuite iru
It's three hours before departure, but I'm already at the airport. (intransitive 着く)
Question 2: state, or action in progress?
Once you're holding a transitive verb, ている becomes available again — but it means something different. A transitive verb + ている is usually the action happening right now, marked with を; a transitive verb + てある is the resulting state, marked with が. The particle is your tell.
母が台所でケーキを焼いている。
haha ga daidokoro de kēki o yaite iru
Mom is baking a cake in the kitchen. (transitive + ている, を → action in progress)
誕生日だから、もうケーキが焼いてある。
tanjōbi da kara, mō kēki ga yaite aru
It's a birthday, so a cake has already been baked (and is ready). (transitive + てある, が → prepared state)
Same verb, 焼く. The を version is a live action you could film; the が version is a finished result sitting on the counter, with the baker implied but off-stage.
When both fit: plain fact vs quiet foresight
Sometimes both an intransitive-ている and a transitive-てある are grammatical for the same scene — the window really is open either way. Now the choice is pure nuance: do you want to flag a hidden, purposeful hand?
- ている (intransitive) = the bare fact. Maybe the wind did it, maybe a person, maybe it was never shut. Not the point.
- てある (transitive) = someone did it, deliberately, and left it so that something — so it's ready, so you can use it, so you'll find it.
暑いね。あ、エアコンがついてる。
atsui ne. a, eakon ga tsuiteru
It's hot. Oh, the AC's on. (just noticing the state → ている)
帰ってくる頃には涼しいように、エアコンがつけてある。
kaette kuru koro ni wa suzushii yō ni, eakon ga tsukete aru
The AC has been left on so it's cool by the time you get back. (deliberate, with a purpose → てある)
ビールなら、冷蔵庫に冷やしてあるよ。
bīru nara, reizōko ni hiyashite aru yo
If it's beer you want, there's some chilling in the fridge (I set it up for you). (foresight → てある)
Notice how the てある versions naturally pull a purpose clause behind them — 〜ように, 〜から, 〜ために. That gravitational pull toward a reason is the fingerprint of てある. If your sentence wants to add "so that…," you want てある. If it sits fine alone as a plain observation, you want ている.
Common mistakes
❌ 道に財布が落としてある。
Wrong nuance — 落としてある says someone dropped it on purpose. A wallet dropped by accident is the neutral intransitive.
✅ 道に財布が落ちている。
michi ni saifu ga ochite iru
There's a wallet lying on the road.
❌ ビールが冷えてある。
Ungrammatical — 冷える is intransitive and rejects てある. Use 冷えている (it's cold) or 冷やしてある (deliberately chilled).
✅ ビールが冷やしてある。
bīru ga hiyashite aru
The beer has been chilled (on purpose, ready for you).
❌ もうケーキを焼いてある。
Wrong particle — the resultant object of てある takes が, not を (を belongs to the in-progress 焼いている).
✅ もうケーキが焼いてある。
mō kēki ga yaite aru
A cake has already been baked (and is ready).
❌ 庭の桜が咲かせてある。
Semantically wrong — nobody 'makes' garden cherry trees bloom, so the deliberate 咲かせてある is off. Blooming is spontaneous.
✅ 庭の桜が咲いている。
niwa no sakura ga saite iru
The cherry tree in the garden is in bloom.
Three of these four are caught by Question 1 alone: match the wrong transitivity to the auxiliary and the sentence breaks. The last one is caught by the foresight test — てある asserts a purposeful agent, so it cannot describe a change nobody caused.
Key takeaways
- Question 1 forces the auxiliary: intransitive verb → ている; transitive verb → てある. You pick the verb, not the auxiliary.
- Question 2 (transitive fork): てある + が is a prepared state; ている + を is the action in progress. Read the particle.
- When both are grammatical, ている states the bare fact and てある flags a person who did it on purpose, usually for a reason — so a 〜ように / 〜から clause signals てある.
- てある needs a real agent and purpose; for accidents and natural changes, fall back to the neutral intransitive + ている.
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Start learning Japanese→Related Topics
- 行く vs 来る: Deictic MovementN4 — Why Japanese picks 行く or 来る by the speaker's own position — not the listener's — and how that same anchor governs 〜ていく／〜てくる in space and in time.
- で: The te-form of the CopulaN4 — で as the te-form of the copula — the connective that chains a noun or na-adjective clause to what follows (学生で、二十歳です), carries a light causal sense (病気で休んだ), and explains why na-adjectives link with で while i-adjectives link with くて.
- なる vs する: Become vs MakeN4 — One axis decides なる or する — is a change happening on its own, or is a doer making or choosing it? — with the が/を particle as a built-in back-check.