93246
> 月日の経つのは早いものだ。

From left to right, the first の marks a genitive case and the second one acts
as a nominalizer. This means that the nominalized clause 経つの is being modified
by 月日, forming a noun phrase 月日の経つの.

> 月日 **の** 経つのは早いものだ。
>

>> _lit._ The passing of time is quick!

However, we could replace the first の with が, which changes the meaning a bit:

> 月日 **が** 経つのは早いものだ。
>

>> _lit._ Time passing is quick!

Because of this, we may think that we have a relative clause although that
would require a noun to modify. To be more precise, that would require the
second の to be an indefinite pronoun, meaning something like "the one", which
wouldn't make sense. 月日が経つの is simply a nominalized clause.

* * *

In short,

  * [[月日]{Noun}] **の** [[経つの]{Nominalized clause}] = [月日の経つの]{Noun Phrase}. The の in bold acts as a **genitive case particle**.
  * [[月日が経つ]{Clause}] **の** = [月日が経つの]{Nominalized clause}. The の in bold acts as a **nominalizer**.

Where's the relative clause?

* * *

By the way, I think 速い is also possible because we're describing its
"quickness".
CC BY-SA 4.0
2022-01-31T06:29:32.673
93234
2022-02-01T06:40:44.170
2022-01-31T21:01:28.147
45630
45630
question
grammar
How to parse 「月日の経つのは早いものだ」
[の](https://dictionary.goo.ne.jp/word/%E3%81%AE/#jn-171157) has the function
of indicating subject (see #2 in the link), so both can be considered as _Time
passing is quick_.

To me, 月日の経つのは... and 月日が... are both fine. In relative clauses modifying a
noun, it is largely interchangeable even if one or the other can sound less
idiomatic.

Examples：

  * 彼の書いた本を読んだ = 彼が書いた本を読んだ
  * 君の言うことはもっともだ = 君が言うことはもっともだ

'Counter-example' from [here](https://jn1et.com/meisishuushoku-no-ga/)

  * Aさんが私に書いた地図 but ✕ Aさんの私に書いた地図

I think the Aさんの... version is still grammatical and acceptable, but
definitely less common.

* * *

[Edit]

I think an (reverse) argument which won't be helpful for learners is that the
second parsing is correct (or at least more natural) exactly because 月日が and
月日の are both possible.

Either way, the subject of 経つ is 月日 and the first parse won't change that and
does not affect the meaning. (Kind of relevant: An English _He insisted on my
reading his new book_ , where _my_ is semantically the subject of _reading_ )

The case for 高田さんが使っていたのを覚えていますか is a bit different mainly because 使う is
transitive. It is actually ambiguous between

  * Do you remember that Takada-san was using **it**?
  * Do you remember the one Takada-san was using?

In English, the bold _it_ can't be omitted but in Japanese それを is omitted in
the first reading. For this example 高田さんの... is possible but strongly suggests
the second reading.

* * *

Regarding 早い/速い for time, both may be used, but my feeling is 早い being more
common. Cf [時間が経つのは「早い」「速い」どっち？](https://oishi-i.net/archives/15142). After
all, a day passes per day...

A general distinction is to use 早い for _early_ and 速い for _fast_.
CC BY-SA 4.0
2022-01-31T08:43:29.167
93235
2022-02-01T01:16:08.630
2022-02-01T01:16:08.630
45489
45489
93234
answer
1. 月日 **の** 経つのは早いものだ。
  2. 月日 **が** 経つのは早いものだ。

These sentences are syntactically exactly the same. Changing の to が doesn't
change the meaning of the sentence a bit. The particles after 月日 are
**subject** markers, and 月日{が/の}経つ is fundamentally a relative clause that
modifies の (which is a noun).

Have you wondered why there is something called "ga-no conversion" in modern
Japanese? You may believe が is the subject marker and の is the genitive case
particle, but this distinction is rather new. In the past, these were almost
the same particle. Both could mark a subject, and both could work as a
possessive particle.

  * [Why can の and が both mark subjects in relative clauses?](https://japanese.stackexchange.com/q/28200/5010)

> Old Japanese, as far as we can tell, didn't have a dedicated subject marker
> - if you wanted a subject that wasn't the topic also, you just left it
> unmarked. It had two genitive particles, though, *nə and *ŋga (modern の and
> が); which varied according to a kind of animacy hierarchy - *ŋga with
> personal pronouns and names IIRC (I've forgotten some of the details), *nə
> with the rest.

  * [「が」vs「の」 with possessives](https://japanese.stackexchange.com/q/39264/5010)
  * [Why is there a が in 深淵に臨むが如し?](https://japanese.stackexchange.com/q/70684/5010)
  * [【古典】古文の格助詞「が」「の」(主格・連体修飾格・同格)](https://kb-study.com/kaku-gano/)

Although が and の have become very different in modern Japanese, this is why
they are still interchangeable inside "relative clauses".

And the concept of "relative clauses" is a bit broader than the English
equivalent. What you know as nominalizers and cleft sentences are actually a
special type of relative clause! Ga-no conversion works also inside these
constructions, as shown below (S = subject marker, A = attributive form of a
verb/adjective/copula, N = modified noun):

  * 太陽 **が** S昇るAのNを見ていた。  
太陽 **の** S昇るAのNを見ていた。  
I was watching the sun rising.

  * 彼 **が** S来るAのNは知らなかった。  
彼 **の** S来るAのNは知らなかった。  
彼 **が** S来るAことNは知らなかった。  
彼 **の** S来るAことNは知らなかった。  
I didn't know that he would come.

  * 彼 **が** S知っているAことNを教えてください。  
彼 **の** S知っているAことNを教えてください。  
Please tell me what he knows.

  * 彼女 **が** S1読んだA1のN1は表紙 **が** S2赤いA2本N2です。  
彼女 **の** S1読んだA1のN1は表紙 **の** S2赤いA2本N2です。  
It is a red-covered book that she read. (cleft sentence)

  * 月日 **が** S1経つA1のN1 **が** S2早いA2ことN2 **が** S3嫌いなA3理由N3 **が** S4分からないA4人N4 **が** S5したA5質問N5  
月日 **の** S1経つA1のN1 **の** S2早いA2ことN2 **の** S3嫌いなA3理由N3 **の** S4分からないA4人N4 **の**
S5したA5質問N5  
a question made by someone who doesn't understand the reason why some people
dislike the fact that time passes quickly

Notice the S-A-N pattern seen consistently in these examples. Don't mix the の
as a subject marker (marked with S) and の as a formal noun (marked with N).

So, after looking at these examples, haven't you started to think it's not
very meaningful to treat one as a subject marker and the other as a genitive
case particle? I'm not suggesting you should stop using the term nominalizer,
but it's worth knowing all of these are ruled by the same principle.
CC BY-SA 4.0
2022-02-01T03:00:21.877
93246
2022-02-01T03:28:33.333
2022-02-01T03:28:33.333
5010
5010
93234
answer
Whether the article is が or の, native speakers see it this way.

> ［月日が／の経つ］の

Having said that, though, I think I know where your doubt is coming from.

Let’s consider the following example.

> 君が飲むのは分かる。

This sentence can be understood as meaning either of the following two.

> I know {what/which/the one} you (are going to) drink.
>
> I understand {that/why} you drink (something).

Now, look at the following sentence, where が is replaced with の.

> 君の飲むのは分かる。

This sentence sounds natural, at least in everyday conversation, only in the
first sense. The second の is interpreted as an indefinite pronoun referring to
a concrete thing, in this case a particular drink.

In the second interpretation of 君が飲むの, on the other hand, the final の means
either “the fact” (こと) or “the reason” (理由) depending on the context. I
suppose the reason 君 **の** 飲むの sounds unnatural in this sense is that the
association between 君 and that の (for こと or 理由) is not direct enough to be
naturally connected with の.

In your example, the final の in 月日が／の経つの is understood as meaning something
like “the way” (様子) or “the pace” (早さ). It is the way or pace _of_ time,
making the linking with の sound natural enough. In fact, you could say 月日の様子
or 月日の早さ, although what the first phrase means is not clear without the verb
経つ.

Let’s look at one more example.

> 君が怒るのは分かる。

Like the example with 飲む above, this sentence could also be understood in two
ways, although most people would understand it in the second meaning unless
context suggests otherwise.

> I know {what/which/the one that} angers you.
>
> I understand why you get angry.

Curiously, 君 **の** 怒るの doesn’t sound quite natural even in the first sense. In
the example with 飲む, the pronoun の represented a drink, and it was _your_
drink (君の飲み物). In this example, however, it represents something external that
causes a certain emotion in _you_. If we had to paraphrase it, it would become
something like 怒らせるもの／やつ. I suppose this is too distant from 君 for the two to
be naturally connected with の.

* * *

[Edit]

As I suggested at the beginning of this post, you should still read 月日の経つの in
the following structure .

> ［月日の経つ］の（＝様子／早さ）

Here, 月日 does work as the subject with respect to the verb 経つ much as in
月日が経つの. (There is no other function it can play within the brackets, after
all.)

However, I think it would be fair to say that we do kind of _feel_ the
implicit association of 月日の様子／早さ transcending the boundary of the brackets.
What I am claiming is that if this association cannot be felt, の may not sound
as natural as が. This is also the case when the clause is long and の is far
away from the modified noun (or nominalizer).
CC BY-SA 4.0
2022-02-01T03:00:30.093
93247
2022-02-01T06:40:44.170
2022-02-01T06:40:44.170
43676
43676
93234
answer