～わけがない

• Reading: わけがない
• Romaji: wake ga nai
• Formation: Verb plain form / Adj / Noun + な + わけがない
• Kanji breakdown: 訳 (わけ) — reason, meaning, explanation

Meaning

A phrase that negates the possibility of something being true, meaning 'there's no way that...' or 'it's impossible that...' It expresses the speaker's strong conviction.

わけがない expresses the speaker's firm belief that something is logically impossible or has no reason to be true. It is stronger than はずがない, which expresses expectation-based impossibility, while わけがない emphasizes that there is no logical basis for the claim. For example, 'あの人が犯人のわけがない' (There's no way that person is the culprit) conveys absolute certainty. The colloquial contracted form わけない can also mean 'easy' (as in 簡単), which is a completely different usage that learners should not confuse. In conversation, わけがない often appears as わけ（が）ないでしょう for slightly softer delivery.

Examples

1. そんな簡単に成功するわけがない。 There's no way it would succeed that easily.
2. 彼が嘘をつくわけがない。 There's no way he would lie.
3. こんなに安いわけがないと思った。 I thought there was no way it could be this cheap.

Usage Guide

Context: spoken, written, everyday

Tone: emphatic

Do Say

• 準備もせずに試験に受かるわけがない。
• あの優しい先生が生徒を叱るわけがない。
• 一日で全部覚えられるわけがないよ。

Don't Say

• そんなことがあるわけがないではない。(Adding ではない after わけがない — double negation creates the opposite meaning) → そんなことがあるわけがない。
• 明日は晴れるわけがない。(Using わけがない for simple weather predictions — わけがない is for logical impossibility, not uncertainty) → 明日は晴れないだろう。

Origin & History

Combines わけ (訳, reason) with がない (does not exist). Literally 'there is no reason for...' expressing logical impossibility.

Cultural Context

Generation: All ages

Social background: Universal