How can we determine the subject of 「彼{かれ}が来{こ}ないことを知{し}りませんでした。」?

Question

Consider the following sentence.

彼{かれ}が来{こ}ないことを知{し}りませんでした。

I really get confused in determining the subject. Which is the correct translation?

1. I did not know that he will not come.

2. He did not know about the absence.

Edit

Roughly speaking, most of the available answers said that the speaker is the person knows about that thing.

However, today I found almost the same sentence quoted from

A Handbook of Japanese Grammar Patterns for Teachers and Leaners on page 317-318,

as follows.

Its translation is apparently contrary to the analysis given in the existing answers. ^{_{I am now in a critical position but committing suicide is not my option.}}

Answer 1

This sentence can technically mean both, but it usually (or almost always) means 1.

To mean 2., we normally say

彼は来ないことを知りませんでした。 = He didn't know about the (someone else's) absense.

because 彼 is the topic of the whole sentence.

In other words, the use of が after 彼 more or less indicates that "彼がこない" is the relative clause which modifies こと.

Answer 2

Understanding the subject of this sentence is a lot easier if we unpack it:

The sentence 彼{かれ}が来{こ}ないことを知{し}りませんでした。has an implicit subject, and since it speaks of knowledge, unless it's a narrative, the subject is probably 自分{じぶん}; the self. What has you confused is probably が looking like part of the sentence; it isn't.

Splitting the sentence up using spaces:

彼が来ないことを　知りません　でした。

In truth, the first clause, everything preceding the を is not really part of the sentence, instead, こと turns a full-fledged free-standing sentence into a clausal noun.

The free-standing sentence that was nouned was probably this: 彼は来ません。

In the process of turning it into a clausal noun, the は was "demoted" to が, as is the custom, and the entire clause became the object of the longer sentence.

Answer 3

1 is the correct translation.

Your sentence in question,

彼が来ないことを知りませんでした。

can also be written as

（私は）彼が来ないことを知りませんでした。

or

彼が来ないことを（私は）知りませんでした。

Which, in both cases, is translated to "I did not know that he will not come."

In your original sentence, the subject is implied to be "I" (私), but not explicitly stated.

「は」is almost always used after a subject. For example,

私はアメリカに住んでいます。

彼は仕事に行きました。

日本はいい国です。

These can be translated to "I live in America.", where "I" is the subject;

"He went to work.", where "He" is the subject;

and "Japan is a good country.", where "Japan" is the subject.