must referee
Verbo regular: referee - refereed- refereed

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must referee
you must referee
she must referee
we must referee
you must referee
they must referee 	I must be refereeing
you must be refereeing
she must be refereeing
we must be refereeing
you must be refereeing
they must be refereeing	I must have refereed
you must have refereed
she must have refereed
we must have refereed
you must have refereed
they must have refereed	I must have been refereeing
you must have been refereeing
she must have been refereeing
we must have been refereeing
you must have been refereeing
they must have been refereeing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not referee
you must not referee
she must not referee
we must not referee
you must not referee
they must not referee 	I must not be refereeing
you must not be refereeing
she must not be refereeing
we must not be refereeing
you must not be refereeing
they must not be refereeing	I must not have refereed
you must not have refereed
she must not have refereed
we must not have refereed
you must not have refereed
they must not have refereed	I must not have been refereeing
you must not have been refereeing
she must not have been refereeing
we must not have been refereeing
you must not have been refereeing
they must not have been refereeing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I referee?
must you referee?
must she referee?
must we referee?
must you referee?
must they referee? 	must I be refereeing?
must you be refereeing?
must she be refereeing?
must we be refereeing?
must you be refereeing?
must they be refereeing? 	must I have refereed?
must you have refereed?
must she have refereed?
must we have refereed?
must you have refereed?
must they have refereed? 	must I have been refereeing?
must you have been refereeing?
must she have been refereeing?
must we have been refereeing?
must you have been refereeing?
must they have been refereeing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not referee?
must you not referee?
must she not referee?
must we not referee?
must you not referee?
must they not referee? 	must I not be refereeing?
must you not be refereeing?
must she not be refereeing?
must we not be refereeing?
must you not be refereeing?
must they not be refereeing? 	must I not have refereed?
must you not have refereed?
must she not have refereed?
must we not have refereed?
must you not have refereed?
must they not have refereed? 	must I not have been refereeing?
must you not have been refereeing?
must she not have been refereeing?
must we not have been refereeing?
must you not have been refereeing?
must they not have been refereeing?