Translation of 答えを知っている人はいませんでした

Question

I started studying Modern Japanese Grammar: A Practical Guide by Naomi McGloin et al. In section 1.2, there's the following example:

[おどろいたことに、] 答えを知っている人はいませんでした。

Which is translated as:

[Surprisingly,] no one knew the answer.

This translation sounds a bit off to me. I'd say that the sentence roughly translates to "[Surprisingly,] the person who know the answer is absent", which isn't equivalent to provided translation. I guess it'd be more adequate if the original sentence was something like "[おどろいたことに、] 誰も答えを知らない". I think that difference between "no one knew" and "person who know was not here" is quite stark. Second one implies presence of someone who know while first one does not.

Is this an error in the book or do I understand it incorrectly?

Answer 1

"To be absent" is not the only translation of いない. Xはいない can mean both of the following:

1. X is (temporarily) not here; X is away; X is absent
2. There is no X (anywhere); X does not exist

You have to determine the correct interpretation from the context. Usually it's fairly easy.

• 宇宙人はいない。 Extraterrestrial intelligence does not exist.
• ネッシーはいない。 There is no Nessie.

Regarding 答えを知っている人はいませんでした, it's indeed ambiguous, at least technically speaking. If 答えを知っている人 has been already introduced in the universe of discourse and a listener/reader understands who is that person in this context, then your interpretation may be possible. Otherwise, "There was no one who knew the answer" is the natural interpretation of this sentence.