っぱなしleft on, left open; non-stop
Someone did something and left it that way: the heater still on, the door still open. With standing, sitting or talking, it means the whole time without a break.
left that way
I went out and accidentally left the heating on.
non-stop
I have been standing for three hours straight since this morning, and my legs hurt.
How to form it
Verb ます-stem + っぱなし
開けます → 開けっぱなし. The result works like a noun: 開けっぱなしだ, 開けっぱなしで, 開けっぱなしの窓.
- Before it
- For "left that way", a one-off action whose result stays: つける, 開ける, 出す, 置く, 脱ぐ. For "non-stop", a posture or an activity: 立つ, 座る, しゃべる.
- After it
- にする when someone leaves it that way, になっている when you find it that way.
- Tone
- Usually a complaint or an admission: it should have been switched off, shut or put away, or it wore you out.
- Where you'll meet it
- Everyday talk, most of all at home. Too casual for formal writing.
In use
Don't leave the window open.
The door has been left open.
The train was crowded, so I had to stand for forty minutes straight.
He talked nonstop throughout the meeting.
Usually neglect, not a plan
English says "I left the light on" whether you forgot or meant to. っぱなし says nobody turned it off afterward, so it usually means you forgot or didn't bother. When you left it on for a reason, ておく says so.
I left the light on.
Nobody turned it off. Usually you forgot, or didn't bother.
I left the light on.
On purpose, so it would be on later.
Close neighbours
たままN4
The same state with no complaint in it. It takes the た-form, not the ます-stem.
I slept with the window open last night.
てあるN4
Someone set it up that way for a reason.
The meeting-room window has been left open for ventilation.
続けるN4
Plain "keep doing", often by choice. っぱなし usually says it was too much.
He kept talking for an hour.
Check yourself
1You forgot to turn the light off. Which do you say?
Choose an answer to see why.
2What happened?
弟が
Choose an answer to see why.
3"I fell asleep with the TV on."
テレビを
Choose an answer to see why.
More detail
It comes from 放す, to let go.
Now and then it is good news:
I laughed all the way through the film.
A 打ちっぱなし is a golf driving range.
On weekends, I practice at the nearby driving range.
More sentences
You must not leave the water running.
I accidentally fell asleep with the air conditioner left on.
Don't leave your socks lying where you took them off.
The meeting-room window had been left open.