must backstroke
Regular verb: backstroke - backstroked- backstroked

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

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

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

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