Not to be confused with the present participle, this structure combines the te form with the verb “to exist” for inanimate objects.
【Verb: te Form】ある
Whereas the te form and the verb いる creates the present continuous state (is doing), the te form with ある expresses that an action has been completed and the result remains. In other words, an action was done intentionally by someone, and that resulting state currently exists.
準備している。
Preparing (currently in the middle of doing it).
準備してある。
The preparation is done [the preparation is in a state of completion].
This is not to be confused with the simple past tense of the verb, although very often the meaning is essentially the same. There are, however, two important differences:
This structure can only be used with transitive verbs because it expresses a state of completion regarding an action that someone has taken intentionally.
Because we are focusing on the resulting state of the object using the verb “to exist” (ある), we must change the direct object particle を to the subject particle が.
鞄をデスクの上に置きました。
I put the bag on top of the desk.
鞄がデスクの上に置いてあります。
The bag has been put on top of the desk (and is still there).
This structure is often used with the verb “to put” (as above) and the verb “to write” as below:
「立入禁止」と書いてある表示を掛ける。
Hang up a sign saying, “Do not enter”.
The JLPT Trap: てある vs. ている (Intransitive)
A classic JLPT N4 trap is contrasting てある (used with transitive verbs) against ている (used with intransitive verbs) to describe the state of an object. The difference lies in human intention.
Transitive + てある: Focuses on the fact that someone did it on purpose and left it that way (often for a specific reason).
Intransitive + ている: Simply states the current physical condition of the object, with no implication of human intent or purpose.
ドアが開けてある。
The door has been left open (someone opened it intentionally, perhaps for ventilation).
ドアが開いている。
The door is open (just stating the current state; maybe the wind blew it open).