YOU SAID:

We should go to the party

INTO JAPANESE

パーティーに行かなくちゃ

BACK INTO ENGLISH

I have to go to the party

INTO JAPANESE

君はパーティーに出なくてはならないよ。

BACK INTO ENGLISH

You have to go to the party. [M]

INTO JAPANESE

君はパーティーに出なくてはならないよ。

BACK INTO ENGLISH

You have to go to the party. [M]