could retrospect
Regular verb: retrospect - retrospected- retrospected

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could retrospect
you could retrospect
she could retrospect
we could retrospect
you could retrospect
they could retrospect 	I could be retrospecting
you could be retrospecting
she could be retrospecting
we could be retrospecting
you could be retrospecting
they could be retrospecting	I could have retrospected
you could have retrospected
she could have retrospected
we could have retrospected
you could have retrospected
they could have retrospected	I could have been retrospecting
you could have been retrospecting
she could have been retrospecting
we could have been retrospecting
you could have been retrospecting
they could have been retrospecting	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not retrospect
you could not retrospect
she could not retrospect
we could not retrospect
you could not retrospect
they could not retrospect 	I could not be retrospecting
you could not be retrospecting
she could not be retrospecting
we could not be retrospecting
you could not be retrospecting
they could not be retrospecting	I could not have retrospected
you could not have retrospected
she could not have retrospected
we could not have retrospected
you could not have retrospected
they could not have retrospected	I could not have been retrospecting
you could not have been retrospecting
she could not have been retrospecting
we could not have been retrospecting
you could not have been retrospecting
they could not have been retrospecting	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I retrospect?
could you retrospect?
could she retrospect?
could we retrospect?
could you retrospect?
could they retrospect? 	could I be retrospecting?
could you be retrospecting?
could she be retrospecting?
could we be retrospecting?
could you be retrospecting?
could they be retrospecting? 	could I have retrospected?
could you have retrospected?
could she have retrospected?
could we have retrospected?
could you have retrospected?
could they have retrospected? 	could I have been retrospecting?
could you have been retrospecting?
could she have been retrospecting?
could we have been retrospecting?
could you have been retrospecting?
could they have been retrospecting? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not retrospect?
could you not retrospect?
could she not retrospect?
could we not retrospect?
could you not retrospect?
could they not retrospect? 	could I not be retrospecting?
could you not be retrospecting?
could she not be retrospecting?
could we not be retrospecting?
could you not be retrospecting?
could they not be retrospecting? 	could I not have retrospected?
could you not have retrospected?
could she not have retrospected?
could we not have retrospected?
could you not have retrospected?
could they not have retrospected? 	could I not have been retrospecting?
could you not have been retrospecting?
could she not have been retrospecting?
could we not have been retrospecting?
could you not have been retrospecting?
could they not have been retrospecting?