Looking up...
いい
ii
good
この本はとてもいいです。
This book is very good.
neutral
Good in quality; pleasant; satisfactory
このケーキはとてもいい匂いがします。
This cake smells really good.
この映画は面白いから、いいと思います。
This movie is interesting, so I think it's good.
Used to describe things that are positive or of high quality. Can also mean 'okay' or 'acceptable' in casual contexts.
informal
Okay; fine; acceptable
A: 今から会議を始めてもいいですか。B: はい、いいですよ。
A: Is it okay if we start the meeting now? B: Yes, it's fine.
Often used in casual conversation to agree or give permission.
neutral
Enough; sufficient
このお金で足りる？ うん、いい。
Will this money be enough? Yeah, it's enough.
Used to indicate that something meets the required amount or standard.
Related Phrases
Pro Tip
Casual vs. Formal
Use 良い (yoi) in formal writing or polite speech, and いい in casual conversation. For example, 良い本 (yoi hon) = 'a good book' in formal contexts, while いい本 (ii hon) is the casual equivalent.
Gold Rule
Conjugation
いい conjugates as an i-adjective: いい → よく (adverb), よくない (negative), よかった (past), よくなかった (past negative).
Word Origin
From Old Japanese *yapi (良い), ultimately from Proto-Japonic *yapi. The kanji 良い (りょう, ryo) is commonly used in formal writing, while いい is the colloquial form.
Usage Notes
いい is the standard colloquial form of 良い. In formal contexts, 良い is preferred. The word can also be used to soften requests or suggestions (e.g., いいですか？ 'Is that okay?').
Word Breakdown
い
adjective ending
suffix和英辞典