could complement
Regular verb: complement - complemented- complemented

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could complement
you could complement
he could complement
we could complement
you could complement
they could complement 	I could be complementing
you could be complementing
he could be complementing
we could be complementing
you could be complementing
they could be complementing	I could have complemented
you could have complemented
he could have complemented
we could have complemented
you could have complemented
they could have complemented	I could have been complementing
you could have been complementing
he could have been complementing
we could have been complementing
you could have been complementing
they could have been complementing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't complement
you couldn't complement
he couldn't complement
we couldn't complement
you couldn't complement
they couldn't complement 	I couldn't be complementing
you couldn't be complementing
he couldn't be complementing
we couldn't be complementing
you couldn't be complementing
they couldn't be complementing	I couldn't have complemented
you couldn't have complemented
he couldn't have complemented
we couldn't have complemented
you couldn't have complemented
they couldn't have complemented	I couldn't have been complementing
you couldn't have been complementing
he couldn't have been complementing
we couldn't have been complementing
you couldn't have been complementing
they couldn't have been complementing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I complement?
could you complement?
could he complement?
could we complement?
could you complement?
could they complement? 	could I be complementing?
could you be complementing?
could he be complementing?
could we be complementing?
could you be complementing?
could they be complementing? 	could I have complemented?
could you have complemented?
could he have complemented?
could we have complemented?
could you have complemented?
could they have complemented? 	could I have been complementing?
could you have been complementing?
could he have been complementing?
could we have been complementing?
could you have been complementing?
could they have been complementing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I complement?
couldn't you complement?
couldn't he complement?
couldn't we complement?
couldn't you complement?
couldn't they complement? 	couldn't I be complementing?
couldn't you be complementing?
couldn't he be complementing?
couldn't we be complementing?
couldn't you be complementing?
couldn't they be complementing? 	couldn't I have complemented?
couldn't you have complemented?
couldn't he have complemented?
couldn't we have complemented?
couldn't you have complemented?
couldn't they have complemented? 	couldn't I have been complementing?
couldn't you have been complementing?
couldn't he have been complementing?
couldn't we have been complementing?
couldn't you have been complementing?
couldn't they have been complementing?