はずだ (hazu da)

Related patterns10

Similar

でしょう
Both predict with confidence, but はずだ shows its work (a schedule, a habit, a calculation). でしょう offers probability on the speaker's authority alone.
だろう
はずだ stakes the claim on reasoning or evidence, だろう is an unbacked guess. Swapping them changes how accountable the speaker is for being wrong.
きっと
はず is a noun, so it takes なのに, だった and がない (はずなのに). きっと only modifies what follows, so none of those shapes exist (×きっとなのに).
も当然とうぜんだ
はずだ predicts what should be true, and can turn out wrong (来くるはずだったのに). のも当然とうぜんだ never predicts, only judges what already happened.
に違ちがいない
はずだ reasons from a known fact, but leaves room to be wrong (はずだったのに). に違ちがいない voices near-total conviction, with no such way out.
に決きまっている
はずだ points at a checkable schedule or fact (三時さんじに着つくはずだ), and survives being wrong (はずだったのに). に決きまっている has no such way out, and taking it back admits unreason.

Opposite

はずがないplain-antonym
The negative lands on the conclusion, not the verb, sharing the same はず. はずだ deduces that X should hold, はずがない deduces that X cannot.

Lookalikes

Same meaning15

probably; might; should be

だろうprobably; I suppose (plain style)attaches at
でしょうprobably; I suppose; right?attaches at
かもしれないmight; may possiblyattaches at
かなI wonder; maybe (wondering aloud)attaches at
かねないcould well (and it wouldn't be good); there's a real chance thatattaches at
まいsurely won't; I shall never — the classical negative of だろう and of （よ）うattaches at
ないとも限かぎらないyou can't rule out that it will happen; it may happen anywayattaches at
に違ちがいないmust be; surely is (a confident conclusion)attaches at
に決きまっているof course it is; is bound to be — treated as beyond argumentattaches at
に相違そういないbeyond doubt; there is no doubt that (written, formal)attaches at
恐おそれがあるthere is a danger that; is at risk of (something unwelcome)attaches at
そうもないshows no sign of; doesn't look like it willattaches at
と考かんがえられるit can reasonably be concluded that; is to be regarded asattaches at
と思おもうI think that; in my opinionattaches at
ような気きがするI have a feeling that; it seems to me thatattaches at

All examples4

should; is supposed to — a confident conclusion drawn from known facts

あいつなら答こたえを知しってるはずだよ。
aitsu nara kotae o shitteru hazu da yo.
If it's him, he should know the answer. casual
荷物にもつは今日きょうの午後ごごに届とどくはずだ。
nimotsu wa kyou no gogo ni todoku hazu da.
The package is supposed to arrive this afternoon. neutral
会議かいぎは三時さんじまでに終おわるはずです。
kaigi wa sanji made ni owaruhazudesu.
The meeting is supposed to end by three o'clock. formal
集合しゅうごう場所ばしょは駅えきのはずだよ。
shuugoubasho wa eki no hazu da yo.
The meeting point is supposed to be the station. casual

How it's formed3

All forms5

はずhazucontraction
味あじわうはず
だ drops sentence-finally in casual speech — もう届とどいてるはず。
はずのhazuno＋名詞めいしadnominal
味あじわうはずの
takes の in front of the noun it modifies — 今日きょう届とどくはずの荷物にもつ, "the parcel that is supposed to arrive today."

pastはずだったhazudatta
味あじわうはずだった
politeはずですhazudesu
味あじわうはずです
て-formはずでhazude
味あじわうはずで

Notes

はずだった means the reasoning was sound but reality defected: 来くるはずだったのに ("he was supposed to come, and yet…").
来こないはずだ calmly expects absence; rejecting a claim outright needs はずがない.