What is this な doing here?


あれ?参加者は20人のはず **な** のに、21人いる。

I'd translate it as follows: "Huh? I'm sure it should be 20 participants, but
21 are here."

I interpreted "should" because のに to my knowledge indicates a surprise here.
Using plain indicative wouldn't reflect that in my opinion.

However, the real "problem" is the bold な. First, I don't know into what
category はず falls (formation morpheme like suffix, or anything else like noun,
verb etc.). Therefore it is hard for me to try to use other grammatical rules
to deduce the meaning of な, like な after nouns in -んです/-のです constructions. And
even if I knew that, I still wouldn't know what function it bears here.




筈{はず} is a noun that roughly means that something is expected to hold true,
and the な is actually the 連体形/attributive form of the particle だ (断定). It's
**not** making はず into an na-adjective.

Basically, there _is_ an expectation "that there should be twenty
participants", and it's being attributed the nominalization particle の,
turning it into a noun-phrase. That に that follows then turns that into
"despite (noun phrase)..."

Your translation is correct :)




筈{はず} is a noun that roughly means that something is expected to hold true,
and the な is actually the 連体形/attributive form of the particle だ (断定). It's
**not** making はず into an na-adjective.

Basically, there _is_ an expectation "that there should be twenty
participants", and it's being attributed the nominalization particle の,
turning it into a noun-phrase. That に that follows then turns that into
"despite (noun phrase)..."

Your translation is correct :)

