Running isn't allowed until your leg is better.
Eating too much sugar isn't allowed.
It's essential she exercises every day.
Wearing a helmet is essential
It's essential that he loses weight.
Taking vitamins isn't essential.
Everyone must wear a helmet.
You mustn't eat too much sugar.
I don't have to take vitamins.
She has to exercise every day.
He has to lose weight.
You must not run while your leg is healing.