how to say "does not make sense"?


I recently wanted to say " _The Japanese counting system does not make sense._
" However, I could not figure out how to communicate the full meaning of "does
not make sense". I don't want to say that it is good, bad, difficult, stupid,
weird, etc. I want to express the closest approximation to the abstract
meaning of " _does not make sense_ ".

I found " **理{り}にかなう** " in a dictionary. I've never even heard「理」used all by
itself. I've only heard it in words such as 「理屈」 and 「理由」. So, I'm not so sure
that that phrase is a natural thing to blurt out in a conversation.

  * Is 「理にかなう」 actually a natural thing to say in daily conversation? Does it have the meaning I want? 
  * The phrase " _makes sense_ " can be used in many contexts, and most of the time it can be talked around using Japanese I somewhat know. But, in the specific case of " _The Japanese counting system does not make sense._ ", how do you capture the nuance?




I think the closest approximation is `訳【わけ】が分からない` (lit. _reason is not
understandable_ ).

> 日本語の数え方は訳が分からない。

This is an informal expression, and depending on the context, this can be used
to express your _subjective_ , personal confusion (does not make sense _to me_
):

> 日本語の数え方は **私にとって** 訳が分からない。

... and to express that something is _objectively_ a mess:

> 日本語の数え方は訳が分からないので、勉強する人は大変だろう。

Indeed the first sentence can be interpreted in both ways, and people may ask
back to you saying 「自分にとって? それとも一般論として?」

* * *

`理にかなう`, `論理的でない` or something like these basically expresses the _objective_
lack of logic:

> 私は、日本語の数え方は理にかなっていないと思う。

This says the Japanese counting system is bad and illogical (to anyone).

And `ちんぷんかんぷん` (noun) is sometimes used, focusing on subjective understanding
of the speaker (It's all _Greek_ to me):

> 日本語の数え方は、私にはちんぷんかんぷんです。




I think the closest approximation is `訳【わけ】が分からない` (lit. _reason is not
understandable_ ).

> 日本語の数え方は訳が分からない。

This is an informal expression, and depending on the context, this can be used
to express your _subjective_ , personal confusion (does not make sense _to me_
):

> 日本語の数え方は **私にとって** 訳が分からない。

... and to express that something is _objectively_ a mess:

> 日本語の数え方は訳が分からないので、勉強する人は大変だろう。

Indeed the first sentence can be interpreted in both ways, and people may ask
back to you saying 「自分にとって? それとも一般論として?」

* * *

`理にかなう`, `論理的でない` or something like these basically expresses the _objective_
lack of logic:

> 私は、日本語の数え方は理にかなっていないと思う。

This says the Japanese counting system is bad and illogical (to anyone).

And `ちんぷんかんぷん` (noun) is sometimes used, focusing on subjective understanding
of the speaker (It's all _Greek_ to me):

> 日本語の数え方は、私にはちんぷんかんぷんです。

