I searched for the word "口惜しゅうて" on the internet but I found "口惜しい". I want to know how "口惜しい" changes to "口惜しゅうて" in the below sentence: "おぬしの生きざま,口惜しゅうて仕方ないわ!"
1 Answer
This is covered in the Wikipedia article on 音便{おんびん} (euphonic change). This is a historical sound change which is simply equivalent to what would be spelled 口惜{くや}しくて.