ない方がいい
It'd be better not to, Shouldn't do
Structure
Explanation
Similar to its positive counterpart, たほうがいい, ないほうがいい is used to give advice that recommends against performing an action.
This pattern is formed by taking the plain negative form of a verb and adding 方, followed by the particle が, and then the い-Adjective, いい.
- その牛乳は古いから、飲まない方がいいですよ。That milk is old, so it'd be better not to drink it.
- あのことは誰にも言わない方がいい。It's best not to tell anyone about that.
The word 方 literally means 'side' or 'option', so this grammar point suggests that the 'not doing' option is the superior choice.
This phrase is very straightforward and often implies that an unwanted result will occur if the advice is not followed.
- 明日、大事な会議があるから、夜更かししない方がいいよ。You have an important meeting tomorrow, so you really shouldn't stay up late. (The negative consequence is being tired for the meeting)
Examples
その牛乳は古いから、飲まないほうがいい。
That milk is old, so it would be better not to drink it.
そのボタンを触らないほうがいい。
It would be better not to touch that button.
道が滑りやすいので、走らないほうがいい。
The road is slippery, so it's better not to run.
大事な約束を忘れないほうがいい。
It would be better not to forget an important promise.
図書館では大声で話さないほうがいいですよ。
It's better not to speak loudly in the library.
まだ準備ができていないから、その箱を開けないほうがいい。
We're not ready yet, so it'd be better not to open that box.
明日の会議に遅れないほうがいい。
It would be better not to be late for tomorrow's meeting.
明日はテストがあるから、夜更かしをしないほうがいい。
You have a test tomorrow, so it would be better not to stay up late.
あまり無理をしないほうがいい。
It would be better not to push yourself too hard.
そんなひどいことを言わないほうがいい。
It would be better not to say such a terrible thing.
あまり心配をしないほうがいいよ。
It's better not to worry so much.
それは高すぎるから、買わないほうがいい。
That's too expensive, so it'd be better not to buy it.