could kill
Regular verb: kill - killed- killed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could kill
you could kill
he could kill
we could kill
you could kill
they could kill 	I could be killing
you could be killing
he could be killing
we could be killing
you could be killing
they could be killing	I could have killed
you could have killed
he could have killed
we could have killed
you could have killed
they could have killed	I could have been killing
you could have been killing
he could have been killing
we could have been killing
you could have been killing
they could have been killing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't kill
you couldn't kill
he couldn't kill
we couldn't kill
you couldn't kill
they couldn't kill 	I couldn't be killing
you couldn't be killing
he couldn't be killing
we couldn't be killing
you couldn't be killing
they couldn't be killing	I couldn't have killed
you couldn't have killed
he couldn't have killed
we couldn't have killed
you couldn't have killed
they couldn't have killed	I couldn't have been killing
you couldn't have been killing
he couldn't have been killing
we couldn't have been killing
you couldn't have been killing
they couldn't have been killing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I kill?
could you kill?
could he kill?
could we kill?
could you kill?
could they kill? 	could I be killing?
could you be killing?
could he be killing?
could we be killing?
could you be killing?
could they be killing? 	could I have killed?
could you have killed?
could he have killed?
could we have killed?
could you have killed?
could they have killed? 	could I have been killing?
could you have been killing?
could he have been killing?
could we have been killing?
could you have been killing?
could they have been killing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I kill?
couldn't you kill?
couldn't he kill?
couldn't we kill?
couldn't you kill?
couldn't they kill? 	couldn't I be killing?
couldn't you be killing?
couldn't he be killing?
couldn't we be killing?
couldn't you be killing?
couldn't they be killing? 	couldn't I have killed?
couldn't you have killed?
couldn't he have killed?
couldn't we have killed?
couldn't you have killed?
couldn't they have killed? 	couldn't I have been killing?
couldn't you have been killing?
couldn't he have been killing?
couldn't we have been killing?
couldn't you have been killing?
couldn't they have been killing?