に決まっているof course; it has to be
You are sure, and you say so flatly: "of course", "obviously", "it has to be". It is your own certainty, mostly spoken, and often impatient.
At this price, it has to be a fake.
in conversation
It's snowing outside, so of course it's cold.
How to form it
Plain form + に決まっている
A noun or a な-adjective drops だ: うそに決まっている, 無理に決まっている. Past and negative go in the word before it: 忘れたに決まっている, 来ないに決まっている. In conversation, に決まってる.
- How sure
- Completely, in your own mind. It is a feeling and not a proof, so you can still be wrong.
- Tone
- Often impatient or scornful: "what else could it be?". As a reply it brushes the other person's doubt aside, and that can reassure too: "of course you'll pass".
- Often with
- どうせ, そんな, あんな, a reason in んだから, and よ or じゃない at the end.
- Where you'll meet it
- Conversation, arguments, and what people say and think in dramas, manga and novels. Not in reports or formal writing.
In use
Who do you think will win this one?
Misaki, obviously. She's the one with experience.
Oh, come on. That's obviously a lie.
If you send an email that rude, of course they will be angry.
With an explanation like that, of course nobody will be convinced.
When it is just 決まる
Straight after a verb or an い-adjective it is always this certainty. After a date, a place or a name it can also be the plain verb 決まる, "to be decided".
The next meeting is bound to be on Monday anyway.
A guess, said as a sure thing: どうせ gives it away.
The next meeting has already been set for Monday.
A report: the date has been fixed. Nobody is judging anything.
Close neighbours
に違いないN3
About as sure, but reasoned out from a clue, and more written than spoken.
The lights are off and there is no answer. They must have gone to bed already.
はずだN4
"Should": an expectation with grounds you could name, such as a schedule or a promise. に決まっている needs none.
According to the schedule, the train should arrive at ten.
Check yourself
1What does this mean?
彼は
Choose an answer to see why.
2Which one is right?
Choose an answer to see why.
More sentences
Of course a child can't carry a box this heavy alone.
She keeps her promises, so of course she will come.
After all that preparation, the presentation is bound to go well.
The shop is right by the station, so of course the rent is high.
They were talking so happily. Of course those two will meet again.