という usage in relative clauses

Question

I'm going through this tae kim's guide lesson about some uses of いう: http://www.guidetojapanese.org/learn/grammar/define

And there is something that I don't understand. In the following sentences:

• 主人公が犯人だったというのが一番面白かった。
• 日本人はお酒に弱いというのは本当？
• 独身だというのは、嘘だったの？
• リブートというのは、パソコンを再起動するということです。

They always use というの. But if I used just の, would it be incorrect? If not, what is the difference? are という and というの interchangeable? Also, they don't say anything about ということ in this lesson, so would the same rules apply?

Answer 1

Adjectival clauses are clauses that modify a noun just as adjectives do. Adjectival clauses in Japanese precede the modified nouns. There are 2 kinds of adjectival clauses:

• Relative clauses

• Noun complement clauses

Relative clauses

The characteristic of relative clauses is the existence of gaps which are the modified nouns.

The girl [whom I met ______ yesterday] is Jane.

「僕が昨日会った」女性はジェーンです。

Noun complement clauses

Unlike relative clauses, noun complement clauses have no gaps.

I got a notification [that my teacher will not come tomorrow] from my friend.

私は、友達から「先生が明日来ない」という知らせを受けた。

Clauses obtained by nominalizing the predicate (in the plain form) with こと and の can also be regarded as noun complement clauses.

I know that the teacher will not come.

先生が来ないのは知っています。

Here, という can be added optionally.

先生が来ないというのは知っています。

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