N3Grammar

といい

It would be nice if, It would be good if, Should, I hope

Structure

Verb［たら］+ いい
Verb［ば］+ いい
Verb + と + いい

［い］Adjective［た］+ ら+ いい
［い］Adjective［い］+ ければ+ いい
［い］Adjective + と + いい

［な］Adjective + だった + ら+ いい
［な］Adjective + であれば+ いい
［な］Adjective + だ + といい

Explanation

By combining the conditional particles たら, ば, or と with the い-Adjective いい, you can express a hope or wish for a particular outcome. All three forms generally mean 'I hope (A) happens' or 'it would be good if (A)'. The choice of particle subtly alters the nuance, indicating how certain the speaker feels that the outcome would be positive.

ばいい - Suggests a hypothetical hope; it would be nice if (A) were to happen. (Weakest nuance/lowest certainty)

たらいい - Expresses a wish for a future event; it will be great if/when (A) happens. (Standard nuance/medium certainty)

といい - Conveys a strong hope or belief that the result of (A) will naturally be good. (Strongest nuance/highest certainty)

To form these expressions, take any verb, conjugate it into its conditional form using ば, たら, or と, and then follow it with the い-Adjective いい.

バスがすぐに来(く)ればいいんだけど、いつも遅(おそ)れるんだよね。
It would be great if the bus came soon, but it's always late.
僕(ぼく)ももっと絵(え)が上手(じょうず)に描(か)けたらいいな。
It would be nice if I could draw pictures better too.
この夏(なつ)は家族(かぞく)みんなで海(うみ)へ行(い)けるといいね。
It would be nice if the whole family can go to the beach this summer, wouldn't it?

Examples

宝(たから)くじが当(あ)たったらいいなあ。

It would be so nice if I won the lottery.

たまにはのんびりしたらいいでしょう。

It would be nice to just take it easy for a change, don't you think?

バスが早(はや)く来(く)るといいですね。

It would be nice if the bus came soon, wouldn't it?

お腹(なか)が空(す)きすぎて泣(な)きそう！何(なに)を食(た)べたらいいのか誰(だれ)か教(おし)えて。

I'm so hungry I could cry! Someone tell me what would be good to eat!

私(わたし)もピアノが上手(じょうず)に弾(ひ)けたらいいのに。

I wish I could play the piano well, too. (it would be good if...)

来年(らいねん)も一緒(いっしょ)にお祭(まつ)りに行(い)けるといいな。

I hope we can go to the festival together next year, too. (it would be good if...)

また同(おな)じクラスになれたらいいね。

I hope we can be in the same class again.

プレゼント、明日(あした)までに届(とど)くといいな。

I hope the present arrives by tomorrow. (it would be good if...)

たくさんあって、どれを選(えら)んだらいいか分(わ)からない。

There are so many, I don't know which one I should choose. (would be good to choose...)

この本(ほん)は面白(おもしろ)いから、読(よ)んでみるといい。

This book is interesting. It would be a good idea for you to try reading it.

分(わ)からなかったら、先生(せんせい)に相談(そうだん)するといい。きっと助(たす)けてくれるよ。

It would be good to consult with your teacher if you don't understand. I'm sure they'll help you.

どの電車(でんしゃ)に乗(の)ったらいいのか、駅員(えきいん)さんに聞(き)いてみましょう。

Let's ask the station attendant which train would be good to take.

疲(つか)れているなら、無理(むり)しないで早(はや)く寝(ね)たらいい。

If you're tired, you should just go to bed early instead of pushing yourself. (it would be good if...)