could regain
Regular verb: regain - regained- regained

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could regain
you could regain
he could regain
we could regain
you could regain
they could regain 	I could be regaining
you could be regaining
he could be regaining
we could be regaining
you could be regaining
they could be regaining	I could have regained
you could have regained
he could have regained
we could have regained
you could have regained
they could have regained	I could have been regaining
you could have been regaining
he could have been regaining
we could have been regaining
you could have been regaining
they could have been regaining	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't regain
you couldn't regain
he couldn't regain
we couldn't regain
you couldn't regain
they couldn't regain 	I couldn't be regaining
you couldn't be regaining
he couldn't be regaining
we couldn't be regaining
you couldn't be regaining
they couldn't be regaining	I couldn't have regained
you couldn't have regained
he couldn't have regained
we couldn't have regained
you couldn't have regained
they couldn't have regained	I couldn't have been regaining
you couldn't have been regaining
he couldn't have been regaining
we couldn't have been regaining
you couldn't have been regaining
they couldn't have been regaining	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I regain?
could you regain?
could he regain?
could we regain?
could you regain?
could they regain? 	could I be regaining?
could you be regaining?
could he be regaining?
could we be regaining?
could you be regaining?
could they be regaining? 	could I have regained?
could you have regained?
could he have regained?
could we have regained?
could you have regained?
could they have regained? 	could I have been regaining?
could you have been regaining?
could he have been regaining?
could we have been regaining?
could you have been regaining?
could they have been regaining? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I regain?
couldn't you regain?
couldn't he regain?
couldn't we regain?
couldn't you regain?
couldn't they regain? 	couldn't I be regaining?
couldn't you be regaining?
couldn't he be regaining?
couldn't we be regaining?
couldn't you be regaining?
couldn't they be regaining? 	couldn't I have regained?
couldn't you have regained?
couldn't he have regained?
couldn't we have regained?
couldn't you have regained?
couldn't they have regained? 	couldn't I have been regaining?
couldn't you have been regaining?
couldn't he have been regaining?
couldn't we have been regaining?
couldn't you have been regaining?
couldn't they have been regaining?