YOU SAID:

I can not believe you've done this

INTO JAPANESE

私はあなたがこれをやったとは信じられない

BACK INTO ENGLISH

i can't believe you did this

INTO JAPANESE

なんて事をしたんだ

BACK INTO ENGLISH

I can't believe you did this.

INTO JAPANESE

なんて事をしたんだ

BACK INTO ENGLISH

I can't believe you did this.