Grammar Info
N4 Lesson 11: 3/23

ば良(よ)かった
Should have, I wish, It would have been better to

Structure
Casual
Formal
Verb[ば]+ よかった

Examples:
食べる → 食べれ + よかった
飲む → 飲め + よかった
する → すれ + よかった
Verb[ば]+ よかった + です

Examples:

食べる → 食べれ + よかった + です
飲む → 飲め + よかった + です
する → すれ + よかった + です
Details
Register Standard
使用域 一般
Information
ばよかった is a common expression used when someone regrets that something has not been/was not done. It is a pairing of the 接続助詞(せつぞくじょし) (conjunction particle) , and the past form of the い-Adjective, 良(い)い (remembering that conjugations of いい use よ, and not い). This construction is often translated to ‘I wish I did (A)’, or ‘I should have done (A)’.
ばよかった is used after verbs, so requires the standard conjugation, before adding よかった.
  • サービスエリア一(ひと)つないじゃないか。高速(こうそく)乗(の)前(まえ)トイレ行(い)けばよかった
    There aren't any service stops, are there? I wish I had gone to the bathroom before we got on the highway.
  • 今日(きょう)残業(ざんぎょう)?昨日(きのう)早(はや)く寝(ね)ればよかった
    I have to work overtime again today? I should have gone to sleep early last night.
As highlights hypothetical situations, ばよかった literally means that ‘it would have been good if (A)’, where (A) is the thing that the speaker wishes had happened.
Fun Fact
This grammar point is in direct contrast to ばいい, the non-past version, which is used to express ‘it would be good if (A)’.
  • 運転(うんてん)たくなかたら、電車(でんしゃ)行(い)けばいい
    If you don't want to drive, it would be better if you went by train.
Slow Male
Hide All
Hide Japanese
Hide English
次(つぎ)電車(でんしゃ)待(ま)てばよかったです
I should have waited for the next train.
Play  
ゲームより勉強(べんきょう)すればよかったです
It would have been better to study rather than play games.
Play  
天気予報(てんきよほう)見(み)ればよかったです
I should have looked at the weather forecast.
Play  
Books
Genki II 1st
Page 120
Genki II 2nd Edition
Page 148
[DBJG] A Dictionary of Basic Japanese Grammar
Page 88