could referee
Regular verb: referee - refereed- refereed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could referee
you could referee
he could referee
we could referee
you could referee
they could referee 	I could be refereeing
you could be refereeing
he could be refereeing
we could be refereeing
you could be refereeing
they could be refereeing	I could have refereed
you could have refereed
he could have refereed
we could have refereed
you could have refereed
they could have refereed	I could have been refereeing
you could have been refereeing
he could have been refereeing
we could have been refereeing
you could have been refereeing
they could have been refereeing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't referee
you couldn't referee
he couldn't referee
we couldn't referee
you couldn't referee
they couldn't referee 	I couldn't be refereeing
you couldn't be refereeing
he couldn't be refereeing
we couldn't be refereeing
you couldn't be refereeing
they couldn't be refereeing	I couldn't have refereed
you couldn't have refereed
he couldn't have refereed
we couldn't have refereed
you couldn't have refereed
they couldn't have refereed	I couldn't have been refereeing
you couldn't have been refereeing
he couldn't have been refereeing
we couldn't have been refereeing
you couldn't have been refereeing
they couldn't have been refereeing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I referee?
could you referee?
could he referee?
could we referee?
could you referee?
could they referee? 	could I be refereeing?
could you be refereeing?
could he be refereeing?
could we be refereeing?
could you be refereeing?
could they be refereeing? 	could I have refereed?
could you have refereed?
could he have refereed?
could we have refereed?
could you have refereed?
could they have refereed? 	could I have been refereeing?
could you have been refereeing?
could he have been refereeing?
could we have been refereeing?
could you have been refereeing?
could they have been refereeing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I referee?
couldn't you referee?
couldn't he referee?
couldn't we referee?
couldn't you referee?
couldn't they referee? 	couldn't I be refereeing?
couldn't you be refereeing?
couldn't he be refereeing?
couldn't we be refereeing?
couldn't you be refereeing?
couldn't they be refereeing? 	couldn't I have refereed?
couldn't you have refereed?
couldn't he have refereed?
couldn't we have refereed?
couldn't you have refereed?
couldn't they have refereed? 	couldn't I have been refereeing?
couldn't you have been refereeing?
couldn't he have been refereeing?
couldn't we have been refereeing?
couldn't you have been refereeing?
couldn't they have been refereeing?