Difference between (て)からというものは and (て)以来？


からというものは and 以来, both appear to share the meaning of "after that event, the
state did not chage. It's always the same". Can someone help me to understand
the difference?




  * 以来 is a relatively simple objective term, "since ～ (, something has been ...)". ～からというもの sounds more dramatic and emphatic, " _ever_ since ～". According to BCCWJ, 以来 is over 30 times more common than からというもの.
  * ～からというもの only follows それ/あれ and the te-form of a verb. 以来 can directly follow a noun, too. 

> あの事故以来、よく眠れません。  
>  [×] あの事故からというもの、よく眠れません。 ← wrong

  * ～からというもの can optionally be followed by the topic marker は. 以来 cannot.
  * 以来 also works as a no-adjective.

> 2015年以来の安値  
>  the lowest price since 2015
>
> 彼を見るのは2月以来だ。  
>  This is the first time I see him after February.




  * 以来 is a relatively simple objective term, "since ～ (, something has been ...)". ～からというもの sounds more dramatic and emphatic, " _ever_ since ～". According to BCCWJ, 以来 is over 30 times more common than からというもの.
  * ～からというもの only follows それ/あれ and the te-form of a verb. 以来 can directly follow a noun, too. 

> あの事故以来、よく眠れません。  
>  [×] あの事故からというもの、よく眠れません。 ← wrong

  * ～からというもの can optionally be followed by the topic marker は. 以来 cannot.
  * 以来 also works as a no-adjective.

> 2015年以来の安値  
>  the lowest price since 2015
>
> 彼を見るのは2月以来だ。  
>  This is the first time I see him after February.

