must gain
Verbo regular: gain - gained- gained

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must gain
you must gain
she must gain
we must gain
you must gain
they must gain 	I must be gaining
you must be gaining
she must be gaining
we must be gaining
you must be gaining
they must be gaining	I must have gained
you must have gained
she must have gained
we must have gained
you must have gained
they must have gained	I must have been gaining
you must have been gaining
she must have been gaining
we must have been gaining
you must have been gaining
they must have been gaining	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I mustn't gain
you mustn't gain
she mustn't gain
we mustn't gain
you mustn't gain
they mustn't gain 	I mustn't be gaining
you mustn't be gaining
she mustn't be gaining
we mustn't be gaining
you mustn't be gaining
they mustn't be gaining	I mustn't have gained
you mustn't have gained
she mustn't have gained
we mustn't have gained
you mustn't have gained
they mustn't have gained	I mustn't have been gaining
you mustn't have been gaining
she mustn't have been gaining
we mustn't have been gaining
you mustn't have been gaining
they mustn't have been gaining	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I gain?
must you gain?
must she gain?
must we gain?
must you gain?
must they gain? 	must I be gaining?
must you be gaining?
must she be gaining?
must we be gaining?
must you be gaining?
must they be gaining? 	must I have gained?
must you have gained?
must she have gained?
must we have gained?
must you have gained?
must they have gained? 	must I have been gaining?
must you have been gaining?
must she have been gaining?
must we have been gaining?
must you have been gaining?
must they have been gaining? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
mustn't I gain?
mustn't you gain?
mustn't she gain?
mustn't we gain?
mustn't you gain?
mustn't they gain? 	mustn't I be gaining?
mustn't you be gaining?
mustn't she be gaining?
mustn't we be gaining?
mustn't you be gaining?
mustn't they be gaining? 	mustn't I have gained?
mustn't you have gained?
mustn't she have gained?
mustn't we have gained?
mustn't you have gained?
mustn't they have gained? 	mustn't I have been gaining?
mustn't you have been gaining?
mustn't she have been gaining?
mustn't we have been gaining?
mustn't you have been gaining?
mustn't they have been gaining?