must stain
Verbo regular: stain - stained- stained

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must stain
you must stain
she must stain
we must stain
you must stain
they must stain 	I must be staining
you must be staining
she must be staining
we must be staining
you must be staining
they must be staining	I must have stained
you must have stained
she must have stained
we must have stained
you must have stained
they must have stained	I must have been staining
you must have been staining
she must have been staining
we must have been staining
you must have been staining
they must have been staining	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not stain
you must not stain
she must not stain
we must not stain
you must not stain
they must not stain 	I must not be staining
you must not be staining
she must not be staining
we must not be staining
you must not be staining
they must not be staining	I must not have stained
you must not have stained
she must not have stained
we must not have stained
you must not have stained
they must not have stained	I must not have been staining
you must not have been staining
she must not have been staining
we must not have been staining
you must not have been staining
they must not have been staining	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I stain?
must you stain?
must she stain?
must we stain?
must you stain?
must they stain? 	must I be staining?
must you be staining?
must she be staining?
must we be staining?
must you be staining?
must they be staining? 	must I have stained?
must you have stained?
must she have stained?
must we have stained?
must you have stained?
must they have stained? 	must I have been staining?
must you have been staining?
must she have been staining?
must we have been staining?
must you have been staining?
must they have been staining? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not stain?
must you not stain?
must she not stain?
must we not stain?
must you not stain?
must they not stain? 	must I not be staining?
must you not be staining?
must she not be staining?
must we not be staining?
must you not be staining?
must they not be staining? 	must I not have stained?
must you not have stained?
must she not have stained?
must we not have stained?
must you not have stained?
must they not have stained? 	must I not have been staining?
must you not have been staining?
must she not have been staining?
must we not have been staining?
must you not have been staining?
must they not have been staining?