Mastering the distinction between -teiru and -tearu to describe states and results of actions.
Context
Describing the Scene
Imagine you walk into a room. You see a window that is open. You notice that someone has left a note on the table. In Japanese, describing these two situations requires different grammatical structures.
When we describe a state that exists naturally (like a window being open), we focus on the result. When we describe a state that exists because someone intentionally performed an action (like leaving a note), we focus on that deliberate preparation.
Explanation
The Grammar of States
We use ～ている for intransitive verbs to describe a state, and ～てある for transitive verbs to describe a state resulting from an intentional action.
Intransitive Verbている/Transitive Verbてある
Use Intransitive + ている to describe the current state of an object, regardless of how it got that way. It simply describes what you see: 'The door is open' (ドアが開いている).
Use Transitive + てある to imply that someone performed an action and left the object in that state. It carries the nuance of preparation: 'The door has been opened (by someone)' (ドアが開けてある).
Tip
Remember: ～てある always uses the particle が to mark the object being described, as it focuses on the state of the object itself.
Examples
Examples in Context
Observe how the choice of verb changes the focus of the sentence.
窓が開いている。
The window is open.
窓まどwindow開いているあいているis open (intransitive)
予約がしてある。
The reservation has been made (and is ready).
予約よやくreservationしてあるしてあるhas been done (transitive)
机の上に本が置いてある。
A book has been placed on the desk.
机つくえdesk本ほんbook置いてあるおいてあるhas been placed
Which sentence implies someone intentionally prepared the item?
電気がついている。
✓ 電気がつけてある。
～てある implies an intentional action was taken by someone to prepare the state.
Usage
Nuance and Usage
Understanding the difference in focus helps you sound more natural.
Focus Comparison
～ている
Focus on the current state.
電気がついている (The light is on).
～てある
Focus on the result of an action.
電気がつけてある (The light has been turned on [for a reason]).
If you walk into a room and notice the heater is on, but you don't know who did it, which is more natural?
暖房がつけてある
✓ 暖房がついている
If you are just observing the state without emphasizing the 'preparer', the intransitive ～ている is more neutral.
Deep dive
Advanced Nuance
A closer look at the intentionality of -tearu.
Why use -tearu?
The -tearu form is often used to show that a task is finished and ready for the next step. For example, 'チケットを買ってある' (I have bought the tickets) implies they are ready for the upcoming trip. It highlights that the 'preparation' phase is complete.
Summary
Lesson Summary
Recap of the key differences.
Use intransitive + ている for states that exist naturally or are simply observed. Use transitive + てある when you want to highlight that someone intentionally performed an action to leave an object in a specific state.