The difference between conjugations of 行く / 行ける and イケる


As an example

「明日、行けなくなっちゃうよ？」(talking about a date etc.)

How can you tell here whether it is 行く negative potential form or イケる negative
form? As far as I can see both look like they'd make sense. イケる still works
written with kanji so I don't know how to tell them apart.




Do you mean [this](https://jisho.org/word/%E8%A1%8C%E3%81%91%E3%82%8B) by イケる?
Then this is etymologically the potential form of 行く. Simply, something like
"go-able" became a fixed phrase meaning "(will) be fine". This イケる is a
derivative fixed expression that is usually used in the non-negative form. We
say イケるよ ("It's gonna be fine"), but we rarely say イケないよ ("It's not gonna be
fine"). For the latter sense, we normally say ダメだよ (or
[いかん](https://jisho.org/word/%E8%A1%8C%E3%81%8B%E3%82%93)よ, although this
sounds pompous) instead.

Therefore, 行けなく in 行けなくなっちゃうよ almost certainly is the negative potential form
of 行く, i.e., "not to be able to go".

> 明日、行けなくなっちゃうよ？  
>  You won't be able to go tomorrow, you know?




Do you mean [this](https://jisho.org/word/%E8%A1%8C%E3%81%91%E3%82%8B) by イケる?
Then this is etymologically the potential form of 行く. Simply, something like
"go-able" became a fixed phrase meaning "(will) be fine". This イケる is a
derivative fixed expression that is usually used in the non-negative form. We
say イケるよ ("It's gonna be fine"), but we rarely say イケないよ ("It's not gonna be
fine"). For the latter sense, we normally say ダメだよ (or
[いかん](https://jisho.org/word/%E8%A1%8C%E3%81%8B%E3%82%93)よ, although this
sounds pompous) instead.

Therefore, 行けなく in 行けなくなっちゃうよ almost certainly is the negative potential form
of 行く, i.e., "not to be able to go".

> 明日、行けなくなっちゃうよ？  
>  You won't be able to go tomorrow, you know?

