6.6.13.1 Read the table and the rules. 1Say the examples in your language.AffirmativeI/You have to go.He/She/it has to go.Negative1/You don't have to goHe/She/it doesn't haveto goWe/You/They don't haveto go.We/You/Theyhave to go.We use have/has to to express obligationI have to take my medicine. (The doctor told me.)• We use don't/doesn't have to to express lackof obligation. You don't have to go to the gymto exercise (it's not necessary.)​

1. Mary was so tired that she couldn’t study any more. (too) Mary was too tired to study any more.2. The boys are too young to play in the street. (old) The boys aren't old enough to play in the street.3. This car is too expensive for him to buy. (not) This car isn't much  expensive for him to buy.4. Jim was so shocked that he couldn’t say anything. (too) Jim was too  shocked to say anything.5. Alice is too short to be a model. (tall) Alice isn’t tall enough to be a model.6. Meeting old friends is always nice. (to) It is always nice to meet old friends.7. Helen was so excited that she couldn’t sleep. (too) Helen was too excited  to sleep.