How to Say “I Should Have…” in Japanese (V-ば + よかったです)

Introduction

Want to say “I wish I had studied” or “I shouldn’t have said that” in Japanese? Use V-ば + よかったです.

This pattern expresses a past regret or the idea that it would have been better if… something had happened.

1. Meaning at a glance

V-ば + よかったです means “I wish I had done … / It would have been better if I had …”.

ケンに愛あいしていると言いえばよかったです。
I wish I had told Ken I loved him.

For negatives, use V-なければ + よかったです to say “I wish I hadn’t … / I shouldn’t have …”.

かなと別わかれなければよかったです。
I shouldn’t have broken up with Kana.

2. How to form the ば-form (conditional)

The V-ば + よかったです structure is formed by changing the verb to its ば-form (conditional form).

Make the ば-form from a verb’s present short form, then add よかったです.

Formation rule (from the slides):

• Affirmative: drop final -u, add -eba.
• Negative: drop ない’s い, add ければ.

Verbs in the affirmative: Drop the final -u and add -eba

Verbs in the negative: Drop the final い and add ければ

3. Natural example sentences

眠ねむたいです。もっと早はやく寝ねればよかったです。
I’m sleepy. I should have gone to bed earlier.

レストランが満席まんせきでした。予約よやくすればよかったです。
The restaurant was full. I should have made a reservation.

おなかがすきました。ごはんを食たべればよかったです。
I’m hungry. I should have eaten something.

虫歯むしばになってしまいました。おかしを食たべなければよかったです。
I got a cavity. I wish I hadn’t eaten sweets.

4. Usage notes

• Affirmative vs. negative regret
  • Affirmative: V-ば + よかった → “I should have done …”
  • Negative: V-なければ + よかった → “I shouldn’t have …”
• Tense/politeness
  • Keep よかったです for polite speech; plain よかった is fine casually.
• Scope
  • This pattern comments on a past situation from now. It does not change the past—only expresses your wish about it.
• Pro Tip: You can express regret about states using adjectives and nouns, too!
  • い-adjectives: Drop the final い (i) and add ければよかった (kereba yokatta). Example: このホテルは高たかいです。 (This hotel is expensive.) → もっと安やすければよかったです。 (I wish it had been cheaper.)
  • な-adjectives / Nouns: Add ならよかった (nara yokatta). Example: 今日きょうは雨あめです。 (It’s raining today.) → 晴はれならよかったです。 (I wish it had been sunny.) この部屋へやは静しずかじゃありません。 (This room isn’t quiet.) → もっと静しずかならよかったです。 (I wish it had been quieter.)

5. Practice Time!

Turn each cue into a regret sentence with V-ば + よかったです (or V-なければ + よかったです).

6. Common mistakes

7. FAQ

Conclusion

Now you can express regrets clearly:

• Build the ば-form (affirmative -えば, negative -なければ) and add よかったです.
• Use affirmative for “I should have …” and negative for “I shouldn’t have …”.

Practice by rewriting three “missed chances” from last week and one “I shouldn’t have …” moment—you’ll have this pattern ready for real conversations.