Dinner Time

I have had some unusual experiences at dinner. My family isn't very religious so we've never really said grace before at dinner. My grandparents however are very religious and before every meal they say grace. One time we were visiting them in Florida and we all sat down to have dinner. Little did I know I would have to be the one to say grace. When my granddad insisted I say the prayer, I had no idea what to say. All I said was "Thank you for the food" and after that the dinner was very awkward. Since then I have practiced my prayers to say before dinner.