Modals: obligaciones y sugerencias

En los cursos avanzados surgen dudas en cuanto a cómo hay que utilizar Can, Have to, Must, be allowed, Should y don´t have, en situaciones donde se prohíbe o se permite algo a alguna persona.

Veamos en un cuadro explicativo cómo diferenciar los modals en inglés:

•    OBLIGATIONS: Must
                                  Have to
•    PROHIBITIONS: Can´t
                                    Musn´t
•    PERMISSION: Can
                                  May
                                  Be allowed
•    SUGGESTIONS: Should/ Shouldn´t
                                     Ought to
                                      World
•    LOCK OF NECCESSARY: Don´t have

Ejercicios para aplicar - Prohibitions and Suggestions

1 We have a lot of work tomorrow. You mustn't  be late.    
   
2 You mustn't  tell anyone what I just told you. It's a secret.
   
3 The museum is free. You  don't have to pay to get in.    
   
4 Children mustn't  tell lies. It's very naughty.    
   
5 John's a millionaire doesn't have to.  He  go to work.    

Ejercicios para aplicar - Prohibitions

1. You can’t park here, sir.
2. You can wear jeans but you can’t wear trainers in that bar.
3. You mustn’t speak when the teacher is speaking.
 
Ejercicios para aplicar - Permission

1. You are allowed to smoke in this area.

2. My roommate reminded me that passengers are allowed to use electronically operated devices in this area.

Ejercicios para aplicar - No obligation

1. You don’t have to wear a tie in our office. You can wear a tie if you want to but it’s OK if you don’t.
2. It’ll be nice if you do but you don’t have to come with me if you don’t want to.
3. You don’t have to dress up for the party. Wear whatever you feel comfortable in.