Modals of Obligation

1. Should

1.1. advice

1.2. personal opinion

1.3. less strong that (must)

1.4. exp: You should sleep early

2. Must

2.1. Advice

2.2. personal opinion

2.3. Stronger than should

2.4. exp. You must see a doctor

3. Have to

3.1. general rule or law

3.2. not an opinion

3.3. exp. You have to wear a seat belt