could prebill
Regular verb: prebill - prebilled- prebilled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could prebill
you could prebill
he could prebill
we could prebill
you could prebill
they could prebill 	I could be prebilling
you could be prebilling
he could be prebilling
we could be prebilling
you could be prebilling
they could be prebilling	I could have prebilled
you could have prebilled
he could have prebilled
we could have prebilled
you could have prebilled
they could have prebilled	I could have been prebilling
you could have been prebilling
he could have been prebilling
we could have been prebilling
you could have been prebilling
they could have been prebilling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not prebill
you could not prebill
he could not prebill
we could not prebill
you could not prebill
they could not prebill 	I could not be prebilling
you could not be prebilling
he could not be prebilling
we could not be prebilling
you could not be prebilling
they could not be prebilling	I could not have prebilled
you could not have prebilled
he could not have prebilled
we could not have prebilled
you could not have prebilled
they could not have prebilled	I could not have been prebilling
you could not have been prebilling
he could not have been prebilling
we could not have been prebilling
you could not have been prebilling
they could not have been prebilling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I prebill?
could you prebill?
could he prebill?
could we prebill?
could you prebill?
could they prebill? 	could I be prebilling?
could you be prebilling?
could he be prebilling?
could we be prebilling?
could you be prebilling?
could they be prebilling? 	could I have prebilled?
could you have prebilled?
could he have prebilled?
could we have prebilled?
could you have prebilled?
could they have prebilled? 	could I have been prebilling?
could you have been prebilling?
could he have been prebilling?
could we have been prebilling?
could you have been prebilling?
could they have been prebilling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not prebill?
could you not prebill?
could he not prebill?
could we not prebill?
could you not prebill?
could they not prebill? 	could I not be prebilling?
could you not be prebilling?
could he not be prebilling?
could we not be prebilling?
could you not be prebilling?
could they not be prebilling? 	could I not have prebilled?
could you not have prebilled?
could he not have prebilled?
could we not have prebilled?
could you not have prebilled?
could they not have prebilled? 	could I not have been prebilling?
could you not have been prebilling?
could he not have been prebilling?
could we not have been prebilling?
could you not have been prebilling?
could they not have been prebilling?