could manipulate
Regular verb: manipulate - manipulated- manipulated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could manipulate
you could manipulate
she could manipulate
we could manipulate
you could manipulate
they could manipulate 	I could be manipulating
you could be manipulating
she could be manipulating
we could be manipulating
you could be manipulating
they could be manipulating	I could have manipulated
you could have manipulated
she could have manipulated
we could have manipulated
you could have manipulated
they could have manipulated	I could have been manipulating
you could have been manipulating
she could have been manipulating
we could have been manipulating
you could have been manipulating
they could have been manipulating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't manipulate
you couldn't manipulate
she couldn't manipulate
we couldn't manipulate
you couldn't manipulate
they couldn't manipulate 	I couldn't be manipulating
you couldn't be manipulating
she couldn't be manipulating
we couldn't be manipulating
you couldn't be manipulating
they couldn't be manipulating	I couldn't have manipulated
you couldn't have manipulated
she couldn't have manipulated
we couldn't have manipulated
you couldn't have manipulated
they couldn't have manipulated	I couldn't have been manipulating
you couldn't have been manipulating
she couldn't have been manipulating
we couldn't have been manipulating
you couldn't have been manipulating
they couldn't have been manipulating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I manipulate?
could you manipulate?
could she manipulate?
could we manipulate?
could you manipulate?
could they manipulate? 	could I be manipulating?
could you be manipulating?
could she be manipulating?
could we be manipulating?
could you be manipulating?
could they be manipulating? 	could I have manipulated?
could you have manipulated?
could she have manipulated?
could we have manipulated?
could you have manipulated?
could they have manipulated? 	could I have been manipulating?
could you have been manipulating?
could she have been manipulating?
could we have been manipulating?
could you have been manipulating?
could they have been manipulating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I manipulate?
couldn't you manipulate?
couldn't she manipulate?
couldn't we manipulate?
couldn't you manipulate?
couldn't they manipulate? 	couldn't I be manipulating?
couldn't you be manipulating?
couldn't she be manipulating?
couldn't we be manipulating?
couldn't you be manipulating?
couldn't they be manipulating? 	couldn't I have manipulated?
couldn't you have manipulated?
couldn't she have manipulated?
couldn't we have manipulated?
couldn't you have manipulated?
couldn't they have manipulated? 	couldn't I have been manipulating?
couldn't you have been manipulating?
couldn't she have been manipulating?
couldn't we have been manipulating?
couldn't you have been manipulating?
couldn't they have been manipulating?