～まい

• Reading: まい
• Romaji: mai
• Formation: Verb dictionary form + まい (する → するまい / すまい)

Meaning

An auxiliary expressing the speaker's negative volition (determination not to do something) or negative conjecture (probably won't happen).

まい has two main uses: negative volition ('I will not / I am determined not to') and negative conjecture ('probably won't / unlikely to'). For negative volition, it is often used with もう二度と (never again) to express firm resolve. For negative conjecture, it functions as the negative equivalent of だろう. It attaches to the dictionary form of Group 2 and Group 3 verbs, and to either the dictionary form or the ます-stem of Group 1 verbs. In modern Japanese, the volition use is more common, while the conjecture use sounds somewhat literary. The phrase ～ようが～まいが means 'whether or not,' showing another usage pattern.

Examples

1. もう二度とあんな失敗はするまいと心に決めた。 I resolved in my heart never to make such a mistake again.
2. こんな寒い日に出かける人はいるまい。 Nobody would go out on such a cold day.
3. 彼はもう来るまいと諦めていた。 He had given up thinking she would no longer come.

Usage Guide

Context: written, spoken, literary

Tone: resolute

Do Say

• もう嘘はつくまいと固く誓った。
• この天気では飛行機は飛ぶまい。
• 彼女が簡単に諦めることはあるまい。

Don't Say

• もう二度と失敗しないまい。(Adding ない before まい — まい already expresses negation, so ない is redundant) → もう二度と失敗するまい。
• 明日は雨が降りますまい。(Attaching まい to ます form — まい attaches to the dictionary form in standard usage) → 明日は雨が降るまい。

Origin & History

まい derives from the classical negative conjectural auxiliary まじ. Over time, まじ evolved into まい, retaining the senses of negative intention and negative conjecture.

Cultural Context

Generation: All ages

Social background: Universal