must checker
Verbo regular: checker - checkered- checkered

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must checker
you must checker
he must checker
we must checker
you must checker
they must checker 	I must be checkering
you must be checkering
he must be checkering
we must be checkering
you must be checkering
they must be checkering	I must have checkered
you must have checkered
he must have checkered
we must have checkered
you must have checkered
they must have checkered	I must have been checkering
you must have been checkering
he must have been checkering
we must have been checkering
you must have been checkering
they must have been checkering	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not checker
you must not checker
he must not checker
we must not checker
you must not checker
they must not checker 	I must not be checkering
you must not be checkering
he must not be checkering
we must not be checkering
you must not be checkering
they must not be checkering	I must not have checkered
you must not have checkered
he must not have checkered
we must not have checkered
you must not have checkered
they must not have checkered	I must not have been checkering
you must not have been checkering
he must not have been checkering
we must not have been checkering
you must not have been checkering
they must not have been checkering	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I checker?
must you checker?
must he checker?
must we checker?
must you checker?
must they checker? 	must I be checkering?
must you be checkering?
must he be checkering?
must we be checkering?
must you be checkering?
must they be checkering? 	must I have checkered?
must you have checkered?
must he have checkered?
must we have checkered?
must you have checkered?
must they have checkered? 	must I have been checkering?
must you have been checkering?
must he have been checkering?
must we have been checkering?
must you have been checkering?
must they have been checkering? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not checker?
must you not checker?
must he not checker?
must we not checker?
must you not checker?
must they not checker? 	must I not be checkering?
must you not be checkering?
must he not be checkering?
must we not be checkering?
must you not be checkering?
must they not be checkering? 	must I not have checkered?
must you not have checkered?
must he not have checkered?
must we not have checkered?
must you not have checkered?
must they not have checkered? 	must I not have been checkering?
must you not have been checkering?
must he not have been checkering?
must we not have been checkering?
must you not have been checkering?
must they not have been checkering?