～はず (expectation)

• Reading: はず
• Romaji: hazu
• Formation: Verb plain form + はず / い-Adj + はず / な-Adj + な + はず / Noun + の + はず

Meaning

A dependent noun expressing the speaker's expectation that something should logically be the case, based on reason, evidence, or prior arrangement. It translates as 'should,' 'is expected to,' or 'is supposed to.'

はず expresses the speaker's logical expectation or confident assumption grounded in facts, schedules, rules, or common sense. It differs from に違いない (gut conviction) and だろう (loose guess) — はず sits between them, based on reasonable grounds. It follows the plain form of verbs and adjectives; for な-adjectives use な + はず, for nouns use の + はず. The negative はずがない means 'there is no way that,' expressing strong denial. はずだった means something was expected but did not happen, conveying disappointment or surprise. It is commonly used when discussing schedules and plans.

Examples

1. 彼女は三時に来るはずだ。 She should arrive at three o'clock.
2. 鍵はかばんの中にあるはずだ。 The key should be in the bag.
3. この問題はそんなに難しくないはずだ。 This problem shouldn't be that difficult.

Usage Guide

Context: spoken, written, everyday

Tone: logical

Do Say

• 電車は五分後に来るはずだ。
• 彼はこのことを知っているはずです。
• 説明書を読めばわかるはずだ。
• 約束したのだから来るはずだ。

Don't Say

• 彼女は静かのはずだ。(な-adjectives need な before はず: 静かなはずだ) → 彼女は静かなはずだ。
• 明日は雨のはずだろう。(はず already expresses expectation — adding だろう is redundant and contradictory) → 明日は雨のはずだ。
• そんなことがあるはずない。(The correct negative form includes が: あるはずがない) → そんなことがあるはずがない。

Origin & History

はず originally referred to the notched end of an arrow where the bowstring rests — something that should fit precisely. This concrete meaning of 'what is expected to fit' extended metaphorically into an expression of logical expectation.

Cultural Context

Generation: All ages

Social background: Universal