もの・
You end on your reason, as a defense: "…so don't blame me". もん sounds sulky or childish, often on purpose.
Don't be so angry. I didn't know.
How to form it
Plain form + もん／もの
Most often after んだ: 寒いんだもん, 休みなんだもん. Straight after a noun or な-adjective it needs だ: 休みだもん.
- Where it goes
- At the end of the sentence. What you are defending comes in the sentence before, or isn't said at all.
- Said to
- Family, friends, a partner. Not a boss, a teacher or a customer.
- Who says it
- Children, all the time. Adults, mostly when they are sulking or playing at it. もの is softer, heard mainly from women and in fiction.
- Where you'll meet it
- At home, among friends, in text messages, anime, manga and dramas.
In use
Why did you leave without saying anything?
Because I suddenly started feeling sick.
I couldn't help it. The train had stopped running.
It's not my fault. I did check properly.
It doesn't have to be a reason. もん also ends a sulky announcement.
Fine. I'll go by myself, then.
Two things to know
It isn't a neutral "because"
It's cold outside, so I don't want to go out today.
A reason.
I don't want to go out today. It's cold outside.
A reason, and a plea: so don't make me.
Sounds odd: すみません、
Sorry I'm late. The train had stopped.
To a boss this sounds like a child answering back. Say 止まっていたんです.
With ね, the sulk goes
もんね says a reason is a fair one, yours or the other person's. Adults say it all the time.
Take it easy. You've been so busy lately.
I'd like to come back to this place, wouldn't you? The food is delicious, after all.
Close neighbours
だってN3
"But…" at the start of a reply. だって opens the excuse and もん closes it, so the two often come as a set.
But it's already closing time.
A reason offered as an apology, and fine in polite speech. This is the one for a boss.
The traffic was terrible, so I ended up being late for the meeting.
Check yourself
1You are late, and your boss asks why. Which do you say?
Choose an answer to see why.
2Which one fits?
今日は
Choose an answer to see why.
3Which one only gives a reason, with no sulk in it?
Choose an answer to see why.
More detail
The full form, もの, in a calmer voice:
It's no wonder he refused. The explanation was far too vague.
After です or ます it is an elegant, old-fashioned way for a woman to talk, met mostly in fiction: だって、うれしいんですもの.
More sentences
I didn't do it on purpose. My hand slipped.
Doing all of it alone is too much. I'm still new here.
I want this seat. You can see the sea from the window.
I'm always the one being kept waiting. Of course I'm fed up.
I don't want to cook today. I'm tired from work.