Help understanding a JLPT N3 conversation (～くらいだから)


This is from a JLPT N3 listening comprehension test on Youtube. This is the
transcript they give in the answer key.

> M: すみません、カバンを落{お｝としたみたいなんですが。
>
> F: 電車｛でんしゃ｝の中｛なか｝じゃないですか？よく忘｛わす｝れる人｛ひと｝がいますから。
>
> M: お酒｛さけ｝を飲｛の｝んだのは、電車｛でんしゃ｝を降｛お｝りてからですから。
>
> F: じゃ、お酒を飲んだ所じゃないんですか。
>
> M: **友達｛ともだち｝がカバンを忘｛わす｝れて、注意｛ちゅうい｝したくらいですから** 。
>
> F: その後どうしました？ ...

I'm not sure I get the last phrase correctly. "It's because my friend forgot
(his?) bag and I took care (of it?)." It doesn't seem to answer the question
being asked (it's the man's bag that is lost, not his friend's). Yet the
police officer seems happy with it and continues with another question.




The idiomatic construction "Clause A くらいだから Clause B" is used to state that
the fact of A serves as a testament to B, a basis for surmising B, or a
justification for saying B. The English expressions " _Given/Since/seeing as_
(and the like) A, B", for the most part, will do as a translation though.
Examples:

> 巨大{きょだい}な雪像{せつぞう}が[1週間]{いっしゅうかん}も建{た}っていられるくらいだから、極寒{ごっかん}である。 ≪The fact
> that those colossal snow sculptures can stand for a full week testifies to
> the sheer coldness (of the place).≫
>
> “ハルキスト”っていうくらいだから村上春樹{むらかみはるき}のこと大好き{だいすき}なわけじゃん。 ≪Given the label
> "Harukists," they adore Haruki Murakami, right? ≫

Now to the sentence in question:

> M: 友達｛ともだち｝がカバンを忘｛わす｝れて、注意｛ちゅうい｝したくらいですから。

With the above-mentioned pattern in mind, the first thing you notice is, apart
from だから changing to ですから for politeness, that there's no Clause B to be seen.
But no worries, this is simply because it is ellipted and implied, and luckily
for us, recovering the lost clause (or at least what its main import is) from
the context is easy enough; It's something that serves to refute the officer's
guesswork offering, likewise with M's previous line. So the complemented
sentence could be any of these:

>
> 友達｛ともだち｝がカバンを忘｛わす｝れて、注意｛ちゅうい｝したくらいですから、｛それはあり得ません/それは違います/そこで忘れたはずはありません/etc.。｝

Another point of note is that "注意｛ちゅうい｝する" means, among other things, to alert
someone to, or even scold them for, their mistake or misconduct.

So all in all, M is reasoning that since he is the one who alerted his friend
to the fact they'd forgotten their bag in the restaurant/bar, the same
watchfulness couldn't have failed to fall upon _his_ bag, at any rate not then
and there, could it?

* * *

It seems there are more interpretations of the sentence than I would have
imagined. Mine is the only one that came naturally to me, and, after
considering other possibilities, still seems most natural to me but I'm just
putting in my two cents' worth.




The idiomatic construction "Clause A くらいだから Clause B" is used to state that
the fact of A serves as a testament to B, a basis for surmising B, or a
justification for saying B. The English expressions " _Given/Since/seeing as_
(and the like) A, B", for the most part, will do as a translation though.
Examples:

> 巨大{きょだい}な雪像{せつぞう}が[1週間]{いっしゅうかん}も建{た}っていられるくらいだから、極寒{ごっかん}である。 ≪The fact
> that those colossal snow sculptures can stand for a full week testifies to
> the sheer coldness (of the place).≫
>
> “ハルキスト”っていうくらいだから村上春樹{むらかみはるき}のこと大好き{だいすき}なわけじゃん。 ≪Given the label
> "Harukists," they adore Haruki Murakami, right? ≫

Now to the sentence in question:

> M: 友達｛ともだち｝がカバンを忘｛わす｝れて、注意｛ちゅうい｝したくらいですから。

With the above-mentioned pattern in mind, the first thing you notice is, apart
from だから changing to ですから for politeness, that there's no Clause B to be seen.
But no worries, this is simply because it is ellipted and implied, and luckily
for us, recovering the lost clause (or at least what its main import is) from
the context is easy enough; It's something that serves to refute the officer's
guesswork offering, likewise with M's previous line. So the complemented
sentence could be any of these:

>
> 友達｛ともだち｝がカバンを忘｛わす｝れて、注意｛ちゅうい｝したくらいですから、｛それはあり得ません/それは違います/そこで忘れたはずはありません/etc.。｝

Another point of note is that "注意｛ちゅうい｝する" means, among other things, to alert
someone to, or even scold them for, their mistake or misconduct.

So all in all, M is reasoning that since he is the one who alerted his friend
to the fact they'd forgotten their bag in the restaurant/bar, the same
watchfulness couldn't have failed to fall upon _his_ bag, at any rate not then
and there, could it?

* * *

It seems there are more interpretations of the sentence than I would have
imagined. Mine is the only one that came naturally to me, and, after
considering other possibilities, still seems most natural to me but I'm just
putting in my two cents' worth.

