YOU SAID:

Sup bro I didn't know you were coming to the party!

INTO JAPANESE

サップブロ私はあなたがパーティーに来ていたことを知らなかった!

BACK INTO ENGLISH

Sapbro I didn't know you were coming to the party!

INTO JAPANESE

サブロ あなたがパーティーに来ているなんて知らなかったわ!

BACK INTO ENGLISH

Saburo I didn't know you were coming to the party!

INTO JAPANESE

三郎 お前がパーティーに来ているなんて知らなかった!

BACK INTO ENGLISH

Saburo I didn't know you were coming to the party!