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
You've done this before, haven't you.