っこない— No Way That'll Happen

• そんな難しい問題、私に分かりっこない。

  Sonna muzukashii mondai, watashi ni wakarikkonai.

  There's no way I could understand such a hard problem.

  Verb ます-stem 分かり + っこない firmly denies any possibility of understanding.

• 宝くじなんて、当たりっこないよ。

  Takarakuji nante, atarikkonai yo.

  There's no way you'll win the lottery.

  ます-stem 当たり + っこない expresses strong conviction it won't happen.

• 今から走っても、間に合いっこない。

  Ima kara hashitte mo, maniaikkonai.

  Even if we run now, there's no way we'll make it.

  ます-stem 間に合い + っこない denies the possibility of making it in time.

• ・Attaches to the ます-stem, e.g. 分かる → 分かりっこない.
• ・Register: casual/spoken only; never in formal writing.
• ・Equivalent in meaning to the more neutral 〜わけがない / 〜はずがない.

Commonly confused with

The JLPT rarely asks whether you recognise a pattern — it asks which of several similar patterns fits. These are the ones っこない is tested against.

• ～おそれがある — There Is a Risk That
• ～ことだ — You Really Should
• ～ことはない — No Need To
• ざるを得ない — No Choice But To
• ～てみせる — I'll Show You I Can
• ～とは限らない — Not Necessarily So
• ～に決まっている — I'm Sure It Must Be
• ～ほかない／～ほかはない — No Choice But To