My notes (mind that they’re still not as I want them):
の and ん
How to add an explanatory tone in Japanese
The particle 「の」as previously mentioned, serves to connect/substitute nouns. However, it has one more function where it’s frequently used. It allows you to give an explanatory tone to your sentence without necessarily turning it into a justification. A lot of the times, it is translated as “It is that”, meaning that the explanation is being given/asked by the speaker.
Conjugation:
- Noun + な + の/ん + だ/です
- Verb + の/ん + だ/です
- I adjective + の/ん + だ/です
- Na adjective + な + の/ん + だ/です
You look at your friend and it looks like he got hurt.
何があった？(1.1)
What happened?
事故があった。(1.2)
There was an accident.
何があったの？(2.1)
What (is it that) happened? (+ looking for further explanation).
事故があったの。でも、安心して！僕は大丈夫だから。(2.2)
(It is that) there here was an accident. Don’t worry though! I am okay.
While the question (1.1) could just imply that you’re asking about what happened and nothing more, (2.1) indicates that there’s an information deficit and that the speaker is looking to know more about what’s being talked about. On the answer side, while (1.2) was simply a description of facts, (2.2) was said with the intention of revealing the missing information. The speaker in this case, could choose to add extra information (or not), compared to a mere description of facts (1.2).
Of course, this information deficit can be added by the speaker anytime, both in a question or in an answer format.
Examples:
早く歩いてください！時間がないんです。
Please hurry up! (It is that) there’s no time.
In this case, the speaker used this to justify the lack of information that might have occurred in the first affirmation.
Using 「のだ」 and 「んだ」 as a way to ask for reassurance:
Sometimes in a question format, you’ll see 「のだ」and 「んだ」being used in yes or no questions. In this case, it’s not necessarily about making an information deficit. I mean, the answer will be a yes or no, so there isn’t much to explore unlike the examples given above. In these cases, you’re actually asking for reassurance/confirmation from the listener.
Examples:
いい？
Is it okay? (More factual, less emotional – “Okay?”).
いいの？
Is it okay? (More about seeking for reassurance, more emotional – “Is it okay?”).
Order of formality:
「の」can be substituted by its casual form 「ん」.
日本に行きます。
I will go to Japan.
日本に行くのです。
日本に行くんです。
日本に行くのだ。
日本に行くんだ。
(It is that) I will go to Japan.
In speech, you’ll find 「ん」being more frequently used compared to 「の」. This is simply because the former gets better integrated in the flow of speech, compared to the later. Read both these two sentences out loud and see which one rolls on your tongue better:
明日友達と遊びたいのだ！
明日友達と遊びたいんだ！
(It is that) I want to hang out with my friends tomorrow.