やしない
(Yashinai)
(emphatic) not at all / definitely not (casual).
Connection rules
- +V ます-stem + やしない (most common) or V ない-form + やしない.
- +Casual emphatic negation — 'definitely won't'.
- +Often in frustrated complaints: 分かりやしない, 聞きやしない.
Examples
1.
そんなこと、分かりやしない。

Sonna koto, wakari yashi nai.
There's no way I'd understand that.
「(emphatic) not at all / definitely not (casual)」
2.
誰も聞きやしないよ。

Dare mo kiki yashi nai yo.
Nobody's going to listen.
「(emphatic) not at all / definitely not (casual)」
Practice
No matter how many times I explain it, he won't understand at all.
何度説明したところで、彼には___よ。
Romaji also accepted