〜はずだ — Japanese Grammar

〜はずだ

Property	Value
Pattern	〜はずだ
JLPT Level	N4
Type	expectation
Formality	Neutral
Register	Both

Meaning

The pattern 〜はずだ (hazu da) expresses a strong expectation or logical conclusion based on a reason or evidence. It translates to "should," "ought to," or "it is expected that." It is used when the speaker is confident that something is true or will happen because of the information they possess.

Structure Formula

[Verb dictionary form] + はずだ
[Verb た-form] + はずだ
[い-adj] + はずだ
[な-adj] + な + はずだ
[Noun] + の + はずだ

• Verbs: Use the dictionary form for present/future expectations and the past (た) form for past expectations.
• い-adjectives: Attach directly to the adjective.
• な-adjectives: Must be followed by な (na) before はずだ.
• Nouns: Must be followed by の (no) before はずだ.

Detailed Explanation

〜はずだ is used when you have a logical basis for your belief. Unlike a simple guess, this pattern implies that you have a reason to think something is the case. For example, if you know a train is scheduled for 8:00, you would say "8時に来るはずだ" (It should arrive at 8:00).

The nuance is one of "logical certainty." If you are surprised that your expectation was wrong, you can use the past tense 〜はずだった (hazu datta), meaning "I expected that [it would be/happen], but..."

This pattern is neutral in formality. In polite speech, use 〜はずです (hazu desu). In casual speech, you can drop the だ (da) at the end, though keeping it adds emphasis to your conviction.

It is important to note that 〜はずだ is generally used for objective expectations. When talking about your own internal feelings or subjective desires, other patterns like 〜つもりだ (tsumori da) are more appropriate.

Example Sentences

Japanese	Reading	Romaji	English
彼はもうすぐ来るはずだ。	かれはもうすぐくるはずだ。	Kare wa mō sugu kuru hazu da.	He should be coming soon.
鍵は机の上にあるはずです。	かぎはつくえのうえにあるはずです。	Kagi wa tsukue no ue ni aru hazu desu.	The key should be on the desk.
昨日は休みだったはずだ。	きのうはやすみだったはずだ。	Kinō wa yasumi datta hazu da.	Yesterday should have been a day off.
この問題は簡単だったはずだ。	このもんだいにかんたんだったはずだ。	Kono mondai wa kantan datta hazu da.	This problem should have been easy.
彼女は学生のはずです。	かのじょはがくせいのはずです。	Kanojo wa gakusei no hazu desu.	She should be a student.
電車は10分前に出たはずだ。	でんしゃはじゅっぷんまえにでたはずだ。	Densha wa juppun mae ni deta hazu da.	The train should have left 10 minutes ago.
彼は忙しいはずだ。	かれはいそがしいはずだ。	Kare wa isogashii hazu da.	He should be busy.
彼は正直なはずだ。	かれはしょうじきなはずだ。	Kare wa shōjiki na hazu da.	He should be honest.

Comparison with Similar Patterns

〜はずだ vs 〜にちがいない (ni chigainai)

Pattern	Nuance
〜はずだ	Logical expectation based on evidence.
〜にちがいない	Strong subjective conviction/certainty.

• 〜はずだ: "Based on the schedule, the shop should be open." (Logical)
• 〜にちがいない: "He is sweating; he must be nervous." (Strong personal conclusion)

〜はずだ vs 〜つもりだ (tsumori da)

• 〜はずだ is for objective expectations about the world or others.
• 〜つもりだ is for your own intentions or your subjective belief about your own actions.
  • Example: "行くはずだ" (He is expected to go) vs "行くつもりだ" (I intend to go).

Common Mistakes

❌ 彼は学生はずだ。 → ✓ 彼は学生のはずだ。

• Correction: Nouns must be connected with の before はず.

❌ 彼は忙しいなはずだ。 → ✓ 彼は忙しいはずだ。

• Correction: い-adjectives do not take "na" before はず.

❌ 私は明日行くはずだ。 → ✓ 私は明日行くつもりだ。

• Correction: Use tsumori for your own intentions, not hazu (which implies an external expectation).

Practice Exercises

Fill in the blank:

1. 彼は今日（来る）______。
2. この店は（有名）______はずです。
3. 昨日は（雨）______はずだったのに、晴れていた。
4. 彼は（先生）______はずだ。
5. この料理は（おいしい）______はずだ。

Answer Key:

1. 来るはずだ (Expectation based on schedule)
2. 有名な (な-adj requires 'na')
3. 雨だった (Past tense expectation)
4. 先生の (Noun requires 'no')
5. おいしい (い-adj connects directly)

JLPT Level Notes

In the JLPT N4, you will often see this in reading comprehension or sentence ordering tasks. Look for keywords like "schedule," "usually," or "I heard that..." which provide the "evidence" for the expectation. If you see a sentence starting with "I intend to...", avoid choosing hazu.