modality N4 common casualpolitewritten
いい — good / fine
いい
Meaning
- good / nice / fine — a positive evaluation; also 'all right / acceptable'
Key sentence
天気がいいから、散歩しよう。
The weather's nice, so let's take a walk.
Formation
| Attaches to | Form | Example |
|---|---|---|
| い-adjective (irregular) | いい → past よかった / neg よくない / adverb よく / て-form よくて | 頭がいい (smart) |
Examples
昨日の映画はとてもよかった。
Yesterday's movie was really good.
今日は気分がよくない。
I don't feel well today.
もっと大きい声で言ったほうがいい。
You'd better speak up louder.
When you can't use it
- いい is irregular: every form except the plain present uses the よ- stem — past よかった, negative よくない, て-form よくて, adverb よく. ×いかった / ×いくない are wrong. (The plain present can be いい or the more formal 良い.)
Notes
- 良い (reading よい) is the same word in a more formal register; いい is the everyday colloquial form. Watch the tone: answering 「コーヒーはいかがですか」 with 「いいです」 (or 結構です) usually *declines* — 'I'm fine, no thanks' — not 'yes, good.'
See いい in real sentences
Jengo shows いい the way you actually meet it: inside real Japanese sentences, so it sticks instead of staying an abstract rule.
Study it in JengoSources Compiled with reference to A Dictionary of Intermediate Japanese Grammar.