はずだhazu da“should be; expected to be”

はずだ means “should be,” “is supposed to,” or “I’m sure that…” It is a JLPT N4 pattern for a conclusion you reach from facts you already know: 三時に出たから、もう着いたはずだ — “He left at three, so he should be there by now.”

The key word is reasoning. はずだ is not a guess and not something you heard from someone else. It is the answer you get when you put the facts together: the schedule, the rules, what someone told you earlier, how things normally work.

はずだ = “Given what I know, this is how it has to be.”

What does はずだ mean?

The noun はず means “expectation” or “what ought to be the case.” はずだ (polite: はずです) turns a sentence into a confident expectation.

• 店は十時に開くはずです。 — The shop should open at ten. (That’s its posted opening time.)
• 彼は来ないはずだ。 — He isn’t supposed to come. (He told me he was busy.)

Depending on context, you will translate it as “should,” “ought to,” “is supposed to,” “must,” or “I’m sure that.” In every case the speaker is fairly certain — much more than with かもしれない — and the certainty comes from a reason, even if that reason is left unsaid.

There is also a past form, はずだった, for plans or expectations that did not work out: 行くはずだった — “I was supposed to go (but didn’t).”

How to form はずだ

はず is a noun, so it attaches the way any noun is modified: plain forms connect directly, な-adjectives keep な, and nouns take の.

To say “was supposed to,” keep the verb in the dictionary form and put the past tense on はず: 来るはずだった. Compare 来たはずだ, which means “he must have come (already).”

When is はずだ used?

• Drawing a conclusion: 電車に乗ったから、もう着いているはずだ.
• Stating what is scheduled or normal: 会議は二時からのはずです.
• Being sure about your own memory: 鍵はかばんに入れたはずなんだけど… — “I’m sure I put the keys in my bag, but…” This is very common when the facts don’t match what you remember.
• Plans that fell through: 旅行に行くはずだったが、病気で行けなかった.
• “No wonder”: when you learn the reason for something, 〜はずだ can mean “that explains it”: 寒いはずだ。雪が降っている — “No wonder it’s cold. It’s snowing.”

はずです is polite and safe in any situation. In casual speech you’ll hear はずだ or just はず at the end: もう着いたはず.

はずだ example sentences

Notice that almost every sentence contains or implies a reason: the train time, the day of the week, three years in Japan. That reason is what licenses はずだ.

Nuance of はずだ

はずだ is about the logic of the situation, not the speaker’s feelings or wishes. If you say 彼は来るはずだ, you mean “by everything I know, he will come” — perhaps he promised, or it’s his shift. If he doesn’t show up, you are surprised, because the facts said otherwise. That surprise is built into はずなのに and はずだったが, which often introduce a complaint or a puzzle.

Because it relies on outside facts, はずだ does not describe your own decisions. You don’t need to reason about what you have decided to do — you just know. For your own plans, use つもり or 予定だ. You can use はずだ about yourself when the outcome depends on things outside your control: 来月から給料が上がるはずだ (“My salary should go up from next month”).

The negative has two shapes. 〜ないはずだ means “it should not be the case” (still an expectation). はずがない is much stronger: “there is no way that…,” rejecting the idea entirely.

💡 はずなのに: add のに and you get “it’s supposed to be…, and yet.” 薬を飲んだはずなのに、まだ頭が痛い — “I’m sure I took the medicine, but my head still hurts.”

はずだ vs でしょう

Both predict something you haven’t confirmed, so English often translates both as “probably” or “should.” The difference is where the certainty comes from.

A forecaster says 晴れるでしょう, because that is the prediction itself. You, having heard the forecast, say 晴れるはずだ, because you are reasoning from it. For the full picture of the guessing scale, read でしょう and then かもしれない, which sits much lower on the certainty ladder.

Common mistakes with はずだ

Is はずだ on the JLPT?

In listening, when you hear 〜はずだったんですが, expect the next line to explain what went wrong. The question will usually ask what actually happened.

Practice questions for はずだ

Learning path for はずだ

Related grammar to review next

• はずがない — the emphatic negative: “there’s no way,” not just “shouldn’t.”
• かもしれない — a low-certainty “maybe,” the opposite end of the scale from はずだ.
• でしょう — a general prediction without the fact-based reasoning.
• つもり — what you use for your own intentions instead of はずだ.
• らしい — a conclusion from what you heard or saw, rather than from your own knowledge.

Learn はずだ with Hane

Hane mixes はずだ, かもしれない, and つもり in the same drills, so you learn to pick by the kind of certainty, not the English word. Practise N4 grammar in Hane.