When the 名詞（めいし） (noun) こと (or 事（こと） in its kanji form) is combined with なの, it conveys an explanatory meaning that is similar to what can be seen in the んです
grammar pattern. As with んです
transforms ‘it is (A)’, into ‘it is that it is (A)’, simply emphasizing the point.
may be seen in several different forms, and is quite often used in conjunction with というのは
. In these types of sentences, というのは
will present the topic, before ことなの
will be used to show the conclusion that the speaker has drawn about that topic.
This expression may be used with any word in its 連体形（れんたいけい） (attributive form), nouns followed by の, or な-Adjectives
followed by な.
Manga artists are people that draw manga.
Accessories are things that come with the main product.
The thing which is ‘for rain to rise’ means ‘to stop raining’.
という may also be used directly before ことなの
. However, this is not always the case, and is even more unlikely when it was already utilized in the first half of the sentence.
Do you mean that person is the most skilled singer?
‘Freight’ means to ship a package.
As というのは is quite long, it will often be shortened to って or とは in casual speech.
is also frequently used when asking questions. This is usually when the speaker has drawn a conclusion about something that has been said, and wants to confirm their understanding.
You mean that it is dangerous to go there alone?
This is not something you should get so worked up over.
なのか is very frequently heard/seen in drama, novels, manga, and similar types of media, but may be considered rude in daily speech.