could cause
Regular verb: cause - caused- caused

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could cause
you could cause
he could cause
we could cause
you could cause
they could cause 	I could be causing
you could be causing
he could be causing
we could be causing
you could be causing
they could be causing	I could have caused
you could have caused
he could have caused
we could have caused
you could have caused
they could have caused	I could have been causing
you could have been causing
he could have been causing
we could have been causing
you could have been causing
they could have been causing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not cause
you could not cause
he could not cause
we could not cause
you could not cause
they could not cause 	I could not be causing
you could not be causing
he could not be causing
we could not be causing
you could not be causing
they could not be causing	I could not have caused
you could not have caused
he could not have caused
we could not have caused
you could not have caused
they could not have caused	I could not have been causing
you could not have been causing
he could not have been causing
we could not have been causing
you could not have been causing
they could not have been causing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I cause?
could you cause?
could he cause?
could we cause?
could you cause?
could they cause? 	could I be causing?
could you be causing?
could he be causing?
could we be causing?
could you be causing?
could they be causing? 	could I have caused?
could you have caused?
could he have caused?
could we have caused?
could you have caused?
could they have caused? 	could I have been causing?
could you have been causing?
could he have been causing?
could we have been causing?
could you have been causing?
could they have been causing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not cause?
could you not cause?
could he not cause?
could we not cause?
could you not cause?
could they not cause? 	could I not be causing?
could you not be causing?
could he not be causing?
could we not be causing?
could you not be causing?
could they not be causing? 	could I not have caused?
could you not have caused?
could he not have caused?
could we not have caused?
could you not have caused?
could they not have caused? 	could I not have been causing?
could you not have been causing?
could he not have been causing?
could we not have been causing?
could you not have been causing?
could they not have been causing?