損なう / 損ねる / 損じる【そこなう / そこねる / そんじる】

損ねる, 損なう and 損じる after a ます-stem mean "fail to do": you meant to, or tried to, and it didn't come off. 損ねる and 損なう are close to interchangeable here, and 損ねる is the one you hear most in conversation.

The failure can be a missed chance or a botched attempt. かきそんじる書き損じる and かきそこなう書き損なう are writing something wrongly, and a spoiled sheet is a かきそんじ書き損じ.

損じる

損じる is the old, formal member of the three. You meet it mostly in かきそんじる書き損じる and in the proverb below, with しそんじる仕損じる ("to botch"), and rarely elsewhere.

On their own: "harm", "damage"

As verbs in their own right, all three take a noun with を and mean "harm", "damage". 損なう goes with health, trust and reputation; 損ねる most often with someone's mood.

Usage notes

These go beyond "fail to" and "harm".

損ねる or そびれる

そびれる also follows a ます-stem, but it only means letting the moment pass for something you meant to do. 損ねる also covers trying and failing.

見損なう

みそこなう見損なう can mean "miss seeing", and also "misjudge someone": みそこなった見損なったよ is "I thought better of you".