What is this いけ **** The problem in this sentence is the predicative. should literally translate into "became weeping". But I'm thoroughly clueless about this before that. I can't even say what form this shall represent.

(to weep) is not relevant.

>
> Taro became unable to go to the toilet.

* : "to go"
* : "to be able to go" (potential form of )
* : "not to be able to go", "to be unable to go" (negative potential form)
* : (continuative/adverbial form of , which connects to )
* : "to become " (see Using with i-adjectives)