よい・いい
The word for “good,” as we know, is いい. What is only made obvious through conjugation is that its non-contracted, formal form よい still remains supreme with any other variant. Meaning, the contraction has only affected its 終止形・連体形.
Conjugation Recap
As stated, the contracted form いい is only utilized in the 終止形・連体形. All other derivations utilize よい.
| Form | Plain Speech | Polite Speech |
| Non-past | よい・いい | よいです・いいです |
| Past | よかった | よかったです |
| Negative | よくない | よくないです |
| Negative Past | よくなかった | よくなかったです |
| て Form | よくて | よくて |
| Adverbial Form (連用形) | よく | よく |
In the example sentences below, it is worth noting that “good” is only a basic translation for よい・いい. In practice, it may also be translated as “fine,” “agreeable,” “sufficient,” “okay,” “beneficial,” etc.
Orthography Note: The primary Kanji spelling of よい・いい is 良い. When written in Kanji, the adjective is typically read as よい. In the conclusion of this lesson, we will also go over other alternative Kanji spellings.
1. 成績が良くなった。
My grades got better.
2. 今週は（お）天気が良くないですね。
The weather this week isn’t good, huh.
3. 運が良かったですね。
(My/our/your/his/her) luck was good, huh.
4. 彼は格好よくて優しいですね。
He is cool and nice, isn’t he?
Phrase Note: 格好良い means “attractive/good-looking/stylish,” and in the spoken language, it is typically contracted to かっこいい.
5. 印象が良くなかったです。
It did not have a good impression.
6. 従業員の対応が良くなかった。
The employees’ handling (of the situation) wasn’t good.
7. 良かった！
Thank goodness!
8. 良いお年を（お迎えください）！
Have a happy New Year!
Phrase Note: This phrase is said right before the New Year begins. Even in the spoken language, よい is still the predominant pronunciation in this set phrase. However, いい would not be wrong.
9. それはよかったですね。
I’m glad (to hear) that.
10. タバコは体に良くないです。
Tobacco is not good for the body.
11. いい景色ですね。
What nice scenery.
12. 彼も腕がいいですよ。
He too has good skill.
Phrase Note: 腕が【よい・いい】 is a set phrase meaning “able/skilled.”
13. 糖尿病に良い食品を教えてください。
Could you please tell me foods that are good for diabetes?
14. 覚悟はいいか？
Are you mentally prepared (for this)?
Tone Note: This sentence is indicative of a superior-inferior relationship in which the speaker is higher in status than the listener.
15. 相性が良いカップルの特徴は何ですか。
What are the characteristics of a couple that suits each other.
Phrase Note: 相性が良い literally means “affinity is good.” The opposite of this is 相性が悪い.
Rejecting an Offer
Whether よい・いい indicates approval or rejection of an offer is based on context, much like how the word “fine” functions in English. As is true in English, the default interpretation is rejecting the offer unless it is prefaced with affirmation.
16. ええ、いいですよ。
Sure, that’s fine.
17. （いや、）いいです。
(No,) I’m fine.
Insulting/Sarcastic Usages
As an extension of its ability to reject an offer, there are a plethora of ways in which よい・いい may be used insultingly or in a sarcastic manner. Note that due to the coarse nature of these phrases, いい is the predominant form, at least in modern speech.
18. もういいです。
That’s enough.
Sentence Note: Even in English, this phrase may be quite offensive depending on the situation.
19. いい加減にしてください！
Please cut it out!
20. いい歳（を）して実家暮らしは恥ずかしい。
Living at one’s parents’ house despite being old enough (not to) is embarrassing.
Phrase Note: いい歳（を）して is a set phrase used to insult someone for something that is unbecoming of their age. Due to its insulting nature, it is not often rendered with よい. The same can be said for the phrases that follow.
21. あんた、いい迷惑だよ。
You’re a real nuisance.
Phrase Note: あんた is a coarse contraction of あなた (you)1.
22. いいざまだ。
It serves (you/him/her/them) right!
23. いい気味だ。
It serves (you/him/her/their) right!
Phrase Note: This phrase is synonymous to Ex. 23 but is derived from a completely different angle. 気味 means “feeling/sensation,” and in this expression, the speaker is reveling in the fact that the referent is facing their karma. Whereas in Ex. 22, ざま means “sorry state,” and so this phrase is mocking the referent for their current state of being.
24. いいご身分だな。
Lucky you.
Phrase Note: ご身分 is a combination of the honorific prefix ご～ and 身分 meaning “social status.” Here, it is being used in the most sarcastic means possible.
Common Set Phrases
As we have seen, there are plenty of set phrases involving よい・いい, but most are not insulting in nature.
25. 朝風呂も気持ち｛よい・いい｝です。
The morning bath also feels good.
26. 鳥たちの心地｛よい・いい｝さえずりに耳を傾ける。
To listen carefully to the pleasant songs of the birds.
Phrase Note: 心地 means “sensation,” and it is seen following the stem of verbs to indicate the “sensation of doing.”
27. 居心地（が・の）良い場所で特別な時間を過ごす。
To spend special time at a cozy place.
28. 高層マンションの最上階は住み心地良いのですか。
Is it comfortable living on the top floor of a high-rise apartment complex?
Reading Note: Due to the presence of ～のですか, it is unlikely that 良い would be read as いい, as doing so would result in an imbalance in formality.
The Adverb よく
The adverbial form よく may mean “nicely/well” or “frequently/often,” but differentiating between these usages requires contextual clues.
29. 歯をよく磨いてください。
Brush your teeth well.
30. 彼は本当によく歯を磨いているかどうかわかりません。
I don’t really know whether or not he brushes his teeth [often/well].
31. よくやりましたね。
Wow, you did well.
32. あの子はお母さんとよく似ていますね。
That child closely resembles his/her mother.
33. それ、最近よく聞きますね。
You here that a lot recently, don’t you.
34. よく電話する相手を登録する。
To register those one often calls.
35. (私は)よくピザを注文します。
I often order pizza.
36. イチゴをよく食べますか。
Do you often eat strawberries?
37. よく聞いてください。
Please listen closely.
38. 彼は、手際よく食器を重ねていました。
He was skillfully stacking tableware.
39. そのカメは運よく長生きしました。
The turtle luckily lived a long life.
Kanji Spellings
In the spoken language, いい dominates よい in daily conversation where it may appear, while よい gives off a far more formal tone. However, in the written language in which よい is dominant, several other spellings are at one’s disposal for depending on the nuance intended.
| Spelling | Nuance |
| 良い | 良い describes something as being best off/most suitable. |
| 善い | 善い describes something indicative of good will. |
| 好い | 好い describes what is most desirable to the speaker. |
| 佳い | 佳い describes an auspicious occasion. |
| 吉い | 吉い describes something brought about by good fortune. |
| 宜い | 宜い describes an agreeable/sufficient circumstance. |
Since writing reform took place at the end of World War II, alternative spellings not listed in the Joyo Kanji List (常用漢字表), by default, are avoided and or simplified to spelling(s) that are listed. In the case of these spellings, only 良い is recognized. As an effect, while the nuance differences listed above are in tune with their traditional senses, in modern writing, it is up to the writer whether to follow the traditional norm or the simplified norm. As for the examples below, the traditional norm is followed.
40. 人助けは善いことだ。
Helping others is a good deed.
41. 週末は好く市場に買い物に行く。
On weekends, I often go to the market to shop.
42. 気立ての好い人と付き合いたいです。
I want to date someone who has a good disposition.
43. 暖かくなり、運動するのに良い季節になりました。
The season has gotten warmer and just right for exercising.
44. 佳い縁談を望もうにも家族の醜聞が酷すぎて絶望的です。
No matter how much I desire for promising marriage talks, my family’s scandals are so horrible that things are hopeless for me.
45. 運が吉い。
To have good fortune.
46. 大變2宜いことだと思ふ。
I think it is a very good thing.
The Dialectical Variant ええ
In many dialects (especially Western Japanese dialects such as Kansai Dialects), including even Tokyo Dialect casual speech nowadays, いい is often rendered as ええ. In these dialects, ええ also notably lacks the ability to conjugate into any other forms than the 終止形・連体形, although this does not detract from how other conjugations may still manifest differently.
47. まあ、ええか。
Oh well, why not.
48a. ええことばっか言ってるだけだよ。(Adapted to Tokyo Dialect)
48b. ええことばっか言っとるだけやで。(Typical Kansai Dialect Iteration)
All (they)’re sayin’ is the nice stuff (they want you to hear).