must attribute
Verbo regular: attribute - attributed- attributed

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must attribute
you must attribute
he must attribute
we must attribute
you must attribute
they must attribute 	I must be attributing
you must be attributing
he must be attributing
we must be attributing
you must be attributing
they must be attributing	I must have attributed
you must have attributed
he must have attributed
we must have attributed
you must have attributed
they must have attributed	I must have been attributing
you must have been attributing
he must have been attributing
we must have been attributing
you must have been attributing
they must have been attributing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not attribute
you must not attribute
he must not attribute
we must not attribute
you must not attribute
they must not attribute 	I must not be attributing
you must not be attributing
he must not be attributing
we must not be attributing
you must not be attributing
they must not be attributing	I must not have attributed
you must not have attributed
he must not have attributed
we must not have attributed
you must not have attributed
they must not have attributed	I must not have been attributing
you must not have been attributing
he must not have been attributing
we must not have been attributing
you must not have been attributing
they must not have been attributing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I attribute?
must you attribute?
must he attribute?
must we attribute?
must you attribute?
must they attribute? 	must I be attributing?
must you be attributing?
must he be attributing?
must we be attributing?
must you be attributing?
must they be attributing? 	must I have attributed?
must you have attributed?
must he have attributed?
must we have attributed?
must you have attributed?
must they have attributed? 	must I have been attributing?
must you have been attributing?
must he have been attributing?
must we have been attributing?
must you have been attributing?
must they have been attributing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not attribute?
must you not attribute?
must he not attribute?
must we not attribute?
must you not attribute?
must they not attribute? 	must I not be attributing?
must you not be attributing?
must he not be attributing?
must we not be attributing?
must you not be attributing?
must they not be attributing? 	must I not have attributed?
must you not have attributed?
must he not have attributed?
must we not have attributed?
must you not have attributed?
must they not have attributed? 	must I not have been attributing?
must you not have been attributing?
must he not have been attributing?
must we not have been attributing?
must you not have been attributing?
must they not have been attributing?