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 mustn't backstroke
you mustn't backstroke
she mustn't backstroke
we mustn't backstroke
you mustn't backstroke
they mustn't backstroke 	I mustn't be backstroking
you mustn't be backstroking
she mustn't be backstroking
we mustn't be backstroking
you mustn't be backstroking
they mustn't be backstroking	I mustn't have backstroked
you mustn't have backstroked
she mustn't have backstroked
we mustn't have backstroked
you mustn't have backstroked
they mustn't have backstroked	I mustn't have been backstroking
you mustn't have been backstroking
she mustn't have been backstroking
we mustn't have been backstroking
you mustn't have been backstroking
they mustn't 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 	
mustn't I backstroke?
mustn't you backstroke?
mustn't she backstroke?
mustn't we backstroke?
mustn't you backstroke?
mustn't they backstroke? 	mustn't I be backstroking?
mustn't you be backstroking?
mustn't she be backstroking?
mustn't we be backstroking?
mustn't you be backstroking?
mustn't they be backstroking? 	mustn't I have backstroked?
mustn't you have backstroked?
mustn't she have backstroked?
mustn't we have backstroked?
mustn't you have backstroked?
mustn't they have backstroked? 	mustn't I have been backstroking?
mustn't you have been backstroking?
mustn't she have been backstroking?
mustn't we have been backstroking?
mustn't you have been backstroking?
mustn't they have been backstroking?