These two patterns describe the same event from opposite ends. 〜ておく narrates the act of preparing something in advance; 〜てある describes the state that the preparing leaves behind. You chill the beer in advance — ビールを冷やしておいた — and now the beer stands chilled — ビールが冷やしてある. One sentence tells what you did; the other tells how things are. Learning to choose between them is learning to choose whether to narrate the action or describe the readiness it produced.
One event, two vantage points
Imagine a single preparatory event: someone chills the beer before the party. There are two honest ways to report it.
- The act: focus on the agent performing the prep — dynamic, forward-looking. This is ておく.
- The result: focus on the state now standing — static, present-facing. This is てある.
パーティーの前に、ビールを冷やしておいた。
pātī no mae ni, bīru o hiyashite oita
I chilled the beer in advance, before the party. (the act)
ビールが冷やしてあるよ。飲んでいいよ。
bīru ga hiyashite aru yo. nonde ii yo
The beer is chilled (and ready). Feel free to have some. (the state)
Same beer, same chilling — but the first sentence puts you and your action in the frame, and the second puts the chilled beer in the frame.
The particle shift: を → が
Because the two patterns spotlight different things, the object moves. With ておく, the thing is still the object of your action, so it keeps を. With てある, the thing has become the subject whose state you're describing, so it's promoted to が.
| Angle | Pattern | Example | Reading |
|---|---|---|---|
| the act (do ahead) | Xを 〜ておく | ビールを冷やしておく | "I chill the beer in advance" |
| the state (stands done) | Xが 〜てある | ビールが冷やしてある | "the beer is (kept) chilled" |
明日のプレゼンのために、資料を準備しておいた。
ashita no purezen no tame ni, shiryō o junbi shite oita
I got the materials ready for tomorrow's presentation. (を — I did the prep)
資料はもう準備してあるので、大丈夫です。
shiryō wa mō junbi shite aru node, daijōbu desu
The materials are already prepared, so we're fine. (state stands ready)
レストランを予約しておいたよ。
resutoran o yoyaku shite oita yo
I booked the restaurant in advance. (を — the act)
予約がしてあるので、並ばずに入れます。
yoyaku ga shite aru node, narabazu ni hairemasu
A reservation has been made, so we can go in without lining up. (が — the state)
てある carries a trace of intention
There's a subtle bonus in てある: because it describes a state that resulted from someone's deliberate action, it quietly implies an agent did it on purpose, for a reason — even when no agent is named. That's exactly the readiness a ておく action leaves behind. Compare it with the intransitive 〜ている state, which merely reports how things are, with no hint of intention.
窓が開けてある。誰かが換気のために開けたんだろう。
mado ga akete aru. dareka ga kanki no tame ni aketa n darō
The window has been left open. Someone must have opened it to air the room out.
ドアに「本日休業」と書いてある。
doa ni honjitsu kyūgyō to kaite aru
The door says 'Closed today.' (someone wrote it there, deliberately)
窓が開けてある says the window is open because someone opened it and left it that way — the purposeful residue of an act. 窓が開いている (intransitive) would just say "the window is open," with no such implication (the wind could have done it).
てある needs a transitive verb
This is the structural catch. てある attaches only to transitive verbs（他動詞, tadōshi） — verbs that take an object and imply an actor: 開ける (open), 貼る (stick), 置く (put), 書く (write), 冷やす (chill). For the intransitive result-state, Japanese uses 〜ている instead. So the pair splits: transitive + てある vs intransitive + ている.
壁にきれいなポスターが貼ってある。
kabe ni kirei na posutā ga hatte aru
A pretty poster is stuck on the wall (someone put it up).
ホワイトボードに、明日の予定が書いてある。
howaitobōdo ni, ashita no yotei ga kaite aru
Tomorrow's schedule is written on the whiteboard.
One honest complication: を〜てある
You will also hear X を 〜てある (窓を開けてある, 準備をしてある). This variant keeps を and leans back toward the ておく feel: it foregrounds the agent's completed preparation rather than the object's state — close in meaning to 〜ておいた, but framed as an accomplished readiness. It's real, and not an error. The clean division to internalize is this: when your point is describing the state, promote the object to が (ビールが冷やしてある); the を〜てある pattern tilts back toward "I've done the prep." When in doubt for the stative "it's ready" reading, use が.
How this differs from English
English collapses these two into a single "the beer is chilled." That one clause can mean either "someone chilled it" (the act, backgrounded) or "it's in a chilled state" (the result) — English simply doesn't grammaticalize the difference. Japanese splits it cleanly: 冷やしておいた foregrounds your doing, 冷やしてある foregrounds the standing result, and the particle (を vs が) tells the listener which frame you've chosen. The mental shift for English speakers is to decide, every time, whether you're narrating an action or describing a readiness — because Japanese makes you commit to one.
Common mistakes
Using が with ておく. ておく describes your action, so the object stays を.
❌ ビールが冷やしておいた。
bīru ga hiyashite oita
Incorrect — ておく narrates the act, so the object keeps を: ビールを.
✅ ビールを冷やしておいた。
bīru o hiyashite oita
I chilled the beer in advance.
Using を〜てある for a plain state description. To describe the readiness that stands, promote the object to が.
❌ ビールを冷やしてある。
bīru o hiyashite aru
Off for 'the beer is chilled (ready)' — the stative reading promotes the object to が.
✅ ビールが冷やしてある。
bīru ga hiyashite aru
The beer is (kept) chilled and ready.
Pairing てある with an intransitive verb. てある needs a transitive verb; the intransitive result-state uses ている.
❌ 窓が開いてある。
mado ga aite aru
Incorrect — 開く is intransitive; use 窓が開けてある (transitive) or 窓が開いている (intransitive state).
✅ 窓が開けてある。
mado ga akete aru
The window has been left open (on purpose).
Using てある to narrate your own action. てある is impersonal and stative; to say "I did the prep," use ておいた.
❌ 私はケーキが作ってある。
watashi wa kēki ga tsukutte aru
Incorrect for 'I made a cake' — てある describes the state, not your action.
✅ 私はケーキを作っておいた。
watashi wa kēki o tsukutte oita
I made a cake in advance.
Writing ある in kanji as an auxiliary. Like the rest of the helper family, the auxiliary is kana.
❌ 冷やして有る。
hiyashite aru
Incorrect — the auxiliary ある is written in kana, not the kanji 有る.
✅ 冷やしてある。
hiyashite aru
It's (been) chilled.
Key takeaways
- ておく = the act (dynamic, agent-focused): "I did X in advance." てある = the state (static, result-focused): "X has been done and stands ready."
- The particle shifts: ておく keeps the object on を (ビールを); てある promotes it to が (ビールが).
- てある quietly implies a deliberate agent behind the state — the residue of a ておく action — unlike the plain intransitive ている.
- てある takes transitive verbs only; for intransitive result-states, use ている (窓が開いている).
- Choosing between them is choosing whether to narrate the action or describe the readiness it left behind.
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Start learning Japanese→Related Topics
- 〜ておく／〜とく: Doing in AdvanceN3 — How 〜ておく (from 置く 'to place') means doing something in advance or leaving it done for later benefit — plus the casual 〜とく／〜どく and the useful やめておく 'I'll pass.'
- 〜てある: Intentional Resultant StateN4 — How a transitive verb plus ある describes a state someone deliberately set up and left in place — 窓が開けてある 'the window has been opened on purpose' — and why the object takes が.
- 〜ている vs 〜てある: Intransitive vs Transitive ResultN3 — The classic minimal pair — intransitive verb + ている (a neutral 'it is in state X') vs transitive verb + てある ('someone put it in state X on purpose') — and how the choice both tracks verb transitivity and foregrounds or hides an agent.
- を: The Direct Object MarkerN5 — How を (written with its own dedicated kana, typed 'wo', read o) marks the direct object of a transitive verb — and why the transitive/intransitive split decides whether を appears at all.