could backstroke
Regular verb: backstroke - backstroked- backstroked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could backstroke
you could backstroke
he could backstroke
we could backstroke
you could backstroke
they could backstroke 	I could be backstroking
you could be backstroking
he could be backstroking
we could be backstroking
you could be backstroking
they could be backstroking	I could have backstroked
you could have backstroked
he could have backstroked
we could have backstroked
you could have backstroked
they could have backstroked	I could have been backstroking
you could have been backstroking
he could have been backstroking
we could have been backstroking
you could have been backstroking
they could have been backstroking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not backstroke
you could not backstroke
he could not backstroke
we could not backstroke
you could not backstroke
they could not backstroke 	I could not be backstroking
you could not be backstroking
he could not be backstroking
we could not be backstroking
you could not be backstroking
they could not be backstroking	I could not have backstroked
you could not have backstroked
he could not have backstroked
we could not have backstroked
you could not have backstroked
they could not have backstroked	I could not have been backstroking
you could not have been backstroking
he could not have been backstroking
we could not have been backstroking
you could not have been backstroking
they could not have been backstroking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I backstroke?
could you backstroke?
could he backstroke?
could we backstroke?
could you backstroke?
could they backstroke? 	could I be backstroking?
could you be backstroking?
could he be backstroking?
could we be backstroking?
could you be backstroking?
could they be backstroking? 	could I have backstroked?
could you have backstroked?
could he have backstroked?
could we have backstroked?
could you have backstroked?
could they have backstroked? 	could I have been backstroking?
could you have been backstroking?
could he have been backstroking?
could we have been backstroking?
could you have been backstroking?
could they have been backstroking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not backstroke?
could you not backstroke?
could he not backstroke?
could we not backstroke?
could you not backstroke?
could they not backstroke? 	could I not be backstroking?
could you not be backstroking?
could he not be backstroking?
could we not be backstroking?
could you not be backstroking?
could they not be backstroking? 	could I not have backstroked?
could you not have backstroked?
could he not have backstroked?
could we not have backstroked?
could you not have backstroked?
could they not have backstroked? 	could I not have been backstroking?
could you not have been backstroking?
could he not have been backstroking?
could we not have been backstroking?
could you not have been backstroking?
could they not have been backstroking?