っこない

expression, suffix

no chance of; certainly not; will never happen

Attaches to the -masu stem of a verb to express strong denial of possibility. Colloquial and emphatic, often used in casual speech.

• こんな難むずかしい問もん題だい、できっこないよ。

  There's no way I can solve such a difficult problem.

• 彼かれが約やく束そくを守まもるなんて、ありっこない。

  It's impossible that he'll keep his promise.