Does わけ as in わけではない and わけがない genuinely mean "reason" or actually means "translation/interpretation?


I've been struggling with the word わけ which is taught as meaning reason, but I
am not convinced "reason" is its true meaning because it doesn't make sense,
especially with the the expression わけがない, sentences become nonsensical. I have
done some research and found that わけ or 訳 is used to mean translate,
translation, interpretation. If I see わけではない and わけがない from the perspective of
"translation/interpretation" these expressions make more sense.

Am I correct?




Disclaimer : I'm not a native speaker, not even an advanced learner, this is
just my current comprehension of the わけ-expressions.

訳 can mean two very different things. When it is read やく, it's
translation/interpretation, but when it's read わけ, it actually really means
reason (as well as meaning/cause/result, it's kind of connected). And it makes
perfect sense, I don't understand why you think it doesn't.

Dictionary check.  
reason : a statement offered in explanation or justification, a rational
ground or motive, the thing that makes some fact intelligible, a cause.

**1. ...わけだ**

This one is complicated, and has been thoroughly analyzed here : [How to end a
sentence in わけ](https://japanese.stackexchange.com/questions/2250/how-to-end-
a-sentence-in-%E3%82%8F%E3%81%91)  
But just looking at the keywords in the graph there is "reason, cause, know
fact, result". It all stem from わけだ meaning "it's the reason/cause for..." and
has been extended in all kind of direction.

**2. ...わけがない**

there is no reason for ... (No rational grounds, no logic, out of common
sense)  
It's a strong negation of a reason for someone to do something or for
something to exist or be in some state. If a friend keep insisting that Santa
Claus is real, at some point you can get annoyed and say :

> サンタクロースがいるわけがない !

There is no reason for Santa Claus to exist ! Santa Claus can't possibly exist
! There can be no Santa Claus!

**3. ...わけにはいかない**

The reason for ... won't go. (The reason for ... is not acceptable)  
One cannot do something due to external pressure, usually common sense/society
rules. Often translated "I can't afford to ..." to stress that we can't do
something because it's not reasonable.

> 隣の部屋で今、赤ちゃんが寝ているので、ピアノを弾くわけにはいかない。 I can't afford to play the piano because
> the baby is sleeping in the next room.

So here clearly it's not because I lack the competence that I can't play the
piano, it's because it's common sense to not wake up a sleeping baby, so "the
reason for playing the piano won't go" (is not acceptable).

**4. ...わけではない**

Mildly deny the previous (and sometimes the following) statement.  
Literally previous statement is not a reason for...

> A：「天気予報によると明日は晴れるだろう。」  
>  B：「雨は降らないわけではない。」

A: The weather forecast calls for clear skies tomorrow.  
Literally B: (this statement is) not a reason for "rain won't fall"  
More natural B: It doesn't mean it won't rain.

This was a quick tour and I'm sure I simplified and misrepresented a lot of
things. The わけ-expressions are now idiomatic expressions, so they have been
extended in all kind of way and the root meaning can be sometimes a bit
blurry. Still I think all of them can be reasonably (^^) traced back to 訳
meaning reason.

Edit : By the way, I would like to add that this post is heavily based on the
Dictionary of Basic Japanese Grammar, as well as this amazing blog post (a
must read IMHO) <https://nihongodaybyday.blogspot.com/2014/05/blog-post.html>

