Have to /must
1-I MUST / HAVE TO VISIT MY FRIEND. IT IS HER BIRTHDAY. 2- SAM HAS TO / MUST WEAR UNIFORM AT SCHOOL. 3- YOU DON'T HAVE TO/ HAVE TO GO TO THE SUPERMARKET. I'LL DO4- YOU DON'T HAVE TO MUSTN'T SWIM IN THIS PART OF THE RIVER. it is very dangerous 5- YOU MUST / DON'T HAVE TO DRINK A LOT OF WATER IN HOT weather.