could flex
Regular verb: flex - flexed- flexed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could flex
you could flex
she could flex
we could flex
you could flex
they could flex 	I could be flexing
you could be flexing
she could be flexing
we could be flexing
you could be flexing
they could be flexing	I could have flexed
you could have flexed
she could have flexed
we could have flexed
you could have flexed
they could have flexed	I could have been flexing
you could have been flexing
she could have been flexing
we could have been flexing
you could have been flexing
they could have been flexing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't flex
you couldn't flex
she couldn't flex
we couldn't flex
you couldn't flex
they couldn't flex 	I couldn't be flexing
you couldn't be flexing
she couldn't be flexing
we couldn't be flexing
you couldn't be flexing
they couldn't be flexing	I couldn't have flexed
you couldn't have flexed
she couldn't have flexed
we couldn't have flexed
you couldn't have flexed
they couldn't have flexed	I couldn't have been flexing
you couldn't have been flexing
she couldn't have been flexing
we couldn't have been flexing
you couldn't have been flexing
they couldn't have been flexing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I flex?
could you flex?
could she flex?
could we flex?
could you flex?
could they flex? 	could I be flexing?
could you be flexing?
could she be flexing?
could we be flexing?
could you be flexing?
could they be flexing? 	could I have flexed?
could you have flexed?
could she have flexed?
could we have flexed?
could you have flexed?
could they have flexed? 	could I have been flexing?
could you have been flexing?
could she have been flexing?
could we have been flexing?
could you have been flexing?
could they have been flexing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I flex?
couldn't you flex?
couldn't she flex?
couldn't we flex?
couldn't you flex?
couldn't they flex? 	couldn't I be flexing?
couldn't you be flexing?
couldn't she be flexing?
couldn't we be flexing?
couldn't you be flexing?
couldn't they be flexing? 	couldn't I have flexed?
couldn't you have flexed?
couldn't she have flexed?
couldn't we have flexed?
couldn't you have flexed?
couldn't they have flexed? 	couldn't I have been flexing?
couldn't you have been flexing?
couldn't she have been flexing?
couldn't we have been flexing?
couldn't you have been flexing?
couldn't they have been flexing?