must surface
Verbo regular: surface - surfaced- surfaced

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must surface
you must surface
he must surface
we must surface
you must surface
they must surface 	I must be surfacing
you must be surfacing
he must be surfacing
we must be surfacing
you must be surfacing
they must be surfacing	I must have surfaced
you must have surfaced
he must have surfaced
we must have surfaced
you must have surfaced
they must have surfaced	I must have been surfacing
you must have been surfacing
he must have been surfacing
we must have been surfacing
you must have been surfacing
they must have been surfacing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not surface
you must not surface
he must not surface
we must not surface
you must not surface
they must not surface 	I must not be surfacing
you must not be surfacing
he must not be surfacing
we must not be surfacing
you must not be surfacing
they must not be surfacing	I must not have surfaced
you must not have surfaced
he must not have surfaced
we must not have surfaced
you must not have surfaced
they must not have surfaced	I must not have been surfacing
you must not have been surfacing
he must not have been surfacing
we must not have been surfacing
you must not have been surfacing
they must not have been surfacing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I surface?
must you surface?
must he surface?
must we surface?
must you surface?
must they surface? 	must I be surfacing?
must you be surfacing?
must he be surfacing?
must we be surfacing?
must you be surfacing?
must they be surfacing? 	must I have surfaced?
must you have surfaced?
must he have surfaced?
must we have surfaced?
must you have surfaced?
must they have surfaced? 	must I have been surfacing?
must you have been surfacing?
must he have been surfacing?
must we have been surfacing?
must you have been surfacing?
must they have been surfacing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not surface?
must you not surface?
must he not surface?
must we not surface?
must you not surface?
must they not surface? 	must I not be surfacing?
must you not be surfacing?
must he not be surfacing?
must we not be surfacing?
must you not be surfacing?
must they not be surfacing? 	must I not have surfaced?
must you not have surfaced?
must he not have surfaced?
must we not have surfaced?
must you not have surfaced?
must they not have surfaced? 	must I not have been surfacing?
must you not have been surfacing?
must he not have been surfacing?
must we not have been surfacing?
must you not have been surfacing?
must they not have been surfacing?