Formation of word "何となく"


I think, the word "何となく" means as below

> somehow or other; for some reason or another;

However, how it has been formed so that it means like above?




何となく is made up of:

  * 何【なん】と: contraction of... 
    * 何【なに】: question-word "what"
    * と: quotative particle "(call/say) that"
  * なく: adverbial form of i-adjective ない ("not be"); "not being, without"

As a whole it means "without 'what'", or in more understandable English
"without naming what (it is)", thus comes to represent a feeling that you
can't pinpoint the specific reason.

Note that this phrase is already an idiom, with an undivided accent
なんとなく{LHHHL} instead of etymological なんと{HLL}なく{HL}.

Similar constructions:

  * [それとなく](https://dictionary.goo.ne.jp/jn/131791/meaning/m0u/) "without (pointing) 'that'" → "implicitly; subtly"
  * 幾度／何度となく "without 'how many times'" → "countless times"
  * [～ともなく](https://japanese.stackexchange.com/q/50260/7810) "without any specific" ([a JLPT N1 grammar](https://japanesetest4you.com/flashcard/learn-jlpt-n1-grammar-%E3%81%A8%E3%82%82%E3%81%AA%E3%81%8F-tomonaku/))




何となく is made up of:

  * 何【なん】と: contraction of... 
    * 何【なに】: question-word "what"
    * と: quotative particle "(call/say) that"
  * なく: adverbial form of i-adjective ない ("not be"); "not being, without"

As a whole it means "without 'what'", or in more understandable English
"without naming what (it is)", thus comes to represent a feeling that you
can't pinpoint the specific reason.

Note that this phrase is already an idiom, with an undivided accent
なんとなく{LHHHL} instead of etymological なんと{HLL}なく{HL}.

Similar constructions:

  * [それとなく](https://dictionary.goo.ne.jp/jn/131791/meaning/m0u/) "without (pointing) 'that'" → "implicitly; subtly"
  * 幾度／何度となく "without 'how many times'" → "countless times"
  * [～ともなく](https://japanese.stackexchange.com/q/50260/7810) "without any specific" ([a JLPT N1 grammar](https://japanesetest4you.com/flashcard/learn-jlpt-n1-grammar-%E3%81%A8%E3%82%82%E3%81%AA%E3%81%8F-tomonaku/))

