must cough
Verbo regular: cough - coughed- coughed

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must cough
you must cough
she must cough
we must cough
you must cough
they must cough 	I must be coughing
you must be coughing
she must be coughing
we must be coughing
you must be coughing
they must be coughing	I must have coughed
you must have coughed
she must have coughed
we must have coughed
you must have coughed
they must have coughed	I must have been coughing
you must have been coughing
she must have been coughing
we must have been coughing
you must have been coughing
they must have been coughing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I mustn't cough
you mustn't cough
she mustn't cough
we mustn't cough
you mustn't cough
they mustn't cough 	I mustn't be coughing
you mustn't be coughing
she mustn't be coughing
we mustn't be coughing
you mustn't be coughing
they mustn't be coughing	I mustn't have coughed
you mustn't have coughed
she mustn't have coughed
we mustn't have coughed
you mustn't have coughed
they mustn't have coughed	I mustn't have been coughing
you mustn't have been coughing
she mustn't have been coughing
we mustn't have been coughing
you mustn't have been coughing
they mustn't have been coughing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I cough?
must you cough?
must she cough?
must we cough?
must you cough?
must they cough? 	must I be coughing?
must you be coughing?
must she be coughing?
must we be coughing?
must you be coughing?
must they be coughing? 	must I have coughed?
must you have coughed?
must she have coughed?
must we have coughed?
must you have coughed?
must they have coughed? 	must I have been coughing?
must you have been coughing?
must she have been coughing?
must we have been coughing?
must you have been coughing?
must they have been coughing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
mustn't I cough?
mustn't you cough?
mustn't she cough?
mustn't we cough?
mustn't you cough?
mustn't they cough? 	mustn't I be coughing?
mustn't you be coughing?
mustn't she be coughing?
mustn't we be coughing?
mustn't you be coughing?
mustn't they be coughing? 	mustn't I have coughed?
mustn't you have coughed?
mustn't she have coughed?
mustn't we have coughed?
mustn't you have coughed?
mustn't they have coughed? 	mustn't I have been coughing?
mustn't you have been coughing?
mustn't she have been coughing?
mustn't we have been coughing?
mustn't you have been coughing?
mustn't they have been coughing?