can referee
Verbo regular: referee - refereed- refereed

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

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

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

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