Japatan
Formation
- V普通形 + はずがない
- いA普通形 + はずがない
- なA + な + はずがない
- N + の + はずがない
Explanation
Based on facts or reasons the speaker knows, this strongly denies a possibility: "It can't possibly be ~." Think of it as the strong negative of 〜はずだ ("should be ~"). It means almost the same as わけがない, but はずがない sounds more like a judgment based on reasons.
Examples
鍵をかけて出かけたから、ドアが 開いているはずがない。
I locked the door when I left, so it can't be open.
田中さんは今海外にいるので、今日の会議に 来るはずがない。
Mr. Tanaka is abroad now, so he can't possibly come to today's meeting.
毎日三時間も練習しているのだから、ピアノが 下手なはずがない。
She practices three hours every day, so she can't possibly be bad at the piano.
あの人は毎朝スーツを着て会社に行くから、学生 のはずがない。
That person goes to the office in a suit every morning, so he can't be a student.
Notes
はずはない is also used. 〜ないはずだ means "should not be ~ / I expect not," which is not as strong a denial as はずがない.
Related grammar
Mini quiz
1あんなにやさしいリンさんが、人の悪口を言う（ ）。
Answer and explanation
Answer: 3 はずがない
"Lin is so kind; she can't possibly say bad things about people." はずがない fits. はずだ and わけだ would suggest she does say bad things, which contradicts あんなにやさしい. ことにする is for one's own decision.
2マリアさんは料理の先生だから、料理が（ ）はずがない。
Answer and explanation
Answer: 2 下手な
"Maria is a cooking teacher, so she can't possibly be bad at cooking." A な-adjective connects to はず with な: 下手なはずがない.
3A「この箱、一人で持てる？」
B「こんなに重い箱、一人で（ ）よ。」
Answer and explanation
Answer: 4 持てるはずがない
A: "Can you carry this box by yourself?" B: "A box this heavy? There's no way I can carry it alone." 持てないはずがない would mean "I can surely carry it," the opposite.
