expression, i-adjective
incomprehensible; nonsensical; puzzling
Describes something that makes no sense, is illogical, or cannot be understood. Often used as a predicate adjective.
彼の説明は訳が分からなかった。
His explanation was incomprehensible.
この文章
This sentence doesn't make sense.
expression
I don't get it; I'm confused; I'm lost
Expresses the speaker's own confusion or inability to understand a situation. Often used as a standalone phrase.
何が起こっているのか、訳が分からない。
I have no idea what's going on.