must mast
Verbo regular: mast - masted- masted

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must mast
you must mast
she must mast
we must mast
you must mast
they must mast 	I must be masting
you must be masting
she must be masting
we must be masting
you must be masting
they must be masting	I must have masted
you must have masted
she must have masted
we must have masted
you must have masted
they must have masted	I must have been masting
you must have been masting
she must have been masting
we must have been masting
you must have been masting
they must have been masting	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I mustn't mast
you mustn't mast
she mustn't mast
we mustn't mast
you mustn't mast
they mustn't mast 	I mustn't be masting
you mustn't be masting
she mustn't be masting
we mustn't be masting
you mustn't be masting
they mustn't be masting	I mustn't have masted
you mustn't have masted
she mustn't have masted
we mustn't have masted
you mustn't have masted
they mustn't have masted	I mustn't have been masting
you mustn't have been masting
she mustn't have been masting
we mustn't have been masting
you mustn't have been masting
they mustn't have been masting	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I mast?
must you mast?
must she mast?
must we mast?
must you mast?
must they mast? 	must I be masting?
must you be masting?
must she be masting?
must we be masting?
must you be masting?
must they be masting? 	must I have masted?
must you have masted?
must she have masted?
must we have masted?
must you have masted?
must they have masted? 	must I have been masting?
must you have been masting?
must she have been masting?
must we have been masting?
must you have been masting?
must they have been masting? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
mustn't I mast?
mustn't you mast?
mustn't she mast?
mustn't we mast?
mustn't you mast?
mustn't they mast? 	mustn't I be masting?
mustn't you be masting?
mustn't she be masting?
mustn't we be masting?
mustn't you be masting?
mustn't they be masting? 	mustn't I have masted?
mustn't you have masted?
mustn't she have masted?
mustn't we have masted?
mustn't you have masted?
mustn't they have masted? 	mustn't I have been masting?
mustn't you have been masting?
mustn't she have been masting?
mustn't we have been masting?
mustn't you have been masting?
mustn't they have been masting?