いい; よい

good

i-adjective

Conjugation Table

Present

いい

Negative

よくない

Past

よかった

Past Negative

よくなかった

Te Form

よくて

Adverbial

よく

Conditional

よければ

Presumptive

いいでしょう

Example Sentences

この本はいいです。

This book is good.

Kono hon wa ii desu.

昨日の天気はよかったです。

The weather yesterday was good.

Kinou no tenki wa yokatta desu.

その映画はよくないです。

That movie is not good.

Sono eiga wa yokunai desu.

Grammar Notes & Usage Tips

•Conjugation Caution:** Although いい is an i-adjective, its past tense form is よかった, not いかった. Remember the irregularity: いい becomes よく when conjugated, like よくない (not good) or よくて (and good).

•Particle Pairing:** When using いい to describe something as good, it pairs well with the particle が. For example, "この本がいい" means "This book is good," emphasizing the specific item being described.

•よい vs. いい:** Both よい and いい mean "good," but いい is more common in conversation, while よい might appear in more formal contexts or written Japanese. Use いい to keep your conversational Japanese natural and friendly.

•Expressing Preference:** When expressing that something is better or preferable, use ほうがいい. For instance, "この道のほうがいい" means "This way is better." This structure is handy for making recommendations or giving advice.

•い-adjective: Conjugates by changing the い ending