must unfasten
Verbo regular: unfasten - unfastened- unfastened

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must unfasten
you must unfasten
she must unfasten
we must unfasten
you must unfasten
they must unfasten 	I must be unfastening
you must be unfastening
she must be unfastening
we must be unfastening
you must be unfastening
they must be unfastening	I must have unfastened
you must have unfastened
she must have unfastened
we must have unfastened
you must have unfastened
they must have unfastened	I must have been unfastening
you must have been unfastening
she must have been unfastening
we must have been unfastening
you must have been unfastening
they must have been unfastening	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I mustn't unfasten
you mustn't unfasten
she mustn't unfasten
we mustn't unfasten
you mustn't unfasten
they mustn't unfasten 	I mustn't be unfastening
you mustn't be unfastening
she mustn't be unfastening
we mustn't be unfastening
you mustn't be unfastening
they mustn't be unfastening	I mustn't have unfastened
you mustn't have unfastened
she mustn't have unfastened
we mustn't have unfastened
you mustn't have unfastened
they mustn't have unfastened	I mustn't have been unfastening
you mustn't have been unfastening
she mustn't have been unfastening
we mustn't have been unfastening
you mustn't have been unfastening
they mustn't have been unfastening	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I unfasten?
must you unfasten?
must she unfasten?
must we unfasten?
must you unfasten?
must they unfasten? 	must I be unfastening?
must you be unfastening?
must she be unfastening?
must we be unfastening?
must you be unfastening?
must they be unfastening? 	must I have unfastened?
must you have unfastened?
must she have unfastened?
must we have unfastened?
must you have unfastened?
must they have unfastened? 	must I have been unfastening?
must you have been unfastening?
must she have been unfastening?
must we have been unfastening?
must you have been unfastening?
must they have been unfastening? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
mustn't I unfasten?
mustn't you unfasten?
mustn't she unfasten?
mustn't we unfasten?
mustn't you unfasten?
mustn't they unfasten? 	mustn't I be unfastening?
mustn't you be unfastening?
mustn't she be unfastening?
mustn't we be unfastening?
mustn't you be unfastening?
mustn't they be unfastening? 	mustn't I have unfastened?
mustn't you have unfastened?
mustn't she have unfastened?
mustn't we have unfastened?
mustn't you have unfastened?
mustn't they have unfastened? 	mustn't I have been unfastening?
mustn't you have been unfastening?
mustn't she have been unfastening?
mustn't we have been unfastening?
mustn't you have been unfastening?
mustn't they have been unfastening?