YOU SAID:

Potter swore that he didn't get turnt for the party.

INTO JAPANESE

ポッターはパーティーに出向かなかったと誓った。

BACK INTO ENGLISH

Potter vowed not to go to the party.

INTO JAPANESE

ポッターはパーティーに行かないと誓った。

BACK INTO ENGLISH

Potter vowed not to go to the party.