わけがない/(わけはない) (wake ga nai wake wa nai): There is no way that
～わけがない/(わけはない) (wake ga nai wake wa nai)
Meaning
There is no way that; it is impossible that
Formation and usage
Plain-form verb or i-adjective + わけがない/わけはない. Present affirmative noun/na-adjective + な/である + わけがない.
Explanation
Strongly rule out a possibility on the basis of reasoning or evidence. In conversation, ga may be omitted to give wake nai. V-nai wake ga nai is a double negative meaning there is no way that the action or event does not happen.
Examples
彼は今海外にいるから、今日ここに来るわけがありません。
He is abroad now, so there is no way he will come here today.
鍵がかかっているのだから、誰でも入れるわけがありません。
It is locked, so there is no way just anyone can get in.
一度も習っていないのに、急にできるわけはありません。
You have never learned it, so there is no way you can suddenly do it.
こんな小さな箱に、全部入るわけがありません。
There is no way everything will fit in such a small box.
朝から何も食べていないのだから、お腹がすかないわけがありません。
You have eaten nothing since morning, so there is no way you are not hungry.
How related patterns differ
わけではない and わけでもない reject an interpretation or generalization. わけがない strongly rules out a possibility; わけない is its colloquial form. わけだ presents a logical conclusion, while わけにはいかない concerns duties or principles that prevent an action.