How to Say “I don’t know.” in Japanese

How do you say “I don’t know.” in Japanese?

Today’s phrase is :

I don’t know.

わかんない。

 wakannai

  • I = わたしは (watashiwa)*
  • don’t know = わかんない (wakannai)

*We do not usually use “わたしは (watashiwa)” in spoken language.

If you want to speak politely, you can say :

わかんないです。

 wakannaidesu