could insulate
Regular verb: insulate - insulated- insulated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could insulate
you could insulate
she could insulate
we could insulate
you could insulate
they could insulate 	I could be insulating
you could be insulating
she could be insulating
we could be insulating
you could be insulating
they could be insulating	I could have insulated
you could have insulated
she could have insulated
we could have insulated
you could have insulated
they could have insulated	I could have been insulating
you could have been insulating
she could have been insulating
we could have been insulating
you could have been insulating
they could have been insulating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't insulate
you couldn't insulate
she couldn't insulate
we couldn't insulate
you couldn't insulate
they couldn't insulate 	I couldn't be insulating
you couldn't be insulating
she couldn't be insulating
we couldn't be insulating
you couldn't be insulating
they couldn't be insulating	I couldn't have insulated
you couldn't have insulated
she couldn't have insulated
we couldn't have insulated
you couldn't have insulated
they couldn't have insulated	I couldn't have been insulating
you couldn't have been insulating
she couldn't have been insulating
we couldn't have been insulating
you couldn't have been insulating
they couldn't have been insulating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I insulate?
could you insulate?
could she insulate?
could we insulate?
could you insulate?
could they insulate? 	could I be insulating?
could you be insulating?
could she be insulating?
could we be insulating?
could you be insulating?
could they be insulating? 	could I have insulated?
could you have insulated?
could she have insulated?
could we have insulated?
could you have insulated?
could they have insulated? 	could I have been insulating?
could you have been insulating?
could she have been insulating?
could we have been insulating?
could you have been insulating?
could they have been insulating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I insulate?
couldn't you insulate?
couldn't she insulate?
couldn't we insulate?
couldn't you insulate?
couldn't they insulate? 	couldn't I be insulating?
couldn't you be insulating?
couldn't she be insulating?
couldn't we be insulating?
couldn't you be insulating?
couldn't they be insulating? 	couldn't I have insulated?
couldn't you have insulated?
couldn't she have insulated?
couldn't we have insulated?
couldn't you have insulated?
couldn't they have insulated? 	couldn't I have been insulating?
couldn't you have been insulating?
couldn't she have been insulating?
couldn't we have been insulating?
couldn't you have been insulating?
couldn't they have been insulating?