YOU SAID:

I must eat all of the food at this party

INTO JAPANESE

私はこのパーティーですべての食べ物を食べなければならない

BACK INTO ENGLISH

I have to eat all the food at this party

INTO JAPANESE

私はこのパーティーですべての食べ物を食べなければならない

BACK INTO ENGLISH

I have to eat all the food at this party