must skivvy
Regular verb: skivvy - skivvied- skivvied

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must skivvy
you must skivvy
he must skivvy
we must skivvy
you must skivvy
they must skivvy 	I must be skivvying
you must be skivvying
he must be skivvying
we must be skivvying
you must be skivvying
they must be skivvying	I must have skivvied
you must have skivvied
he must have skivvied
we must have skivvied
you must have skivvied
they must have skivvied	I must have been skivvying
you must have been skivvying
he must have been skivvying
we must have been skivvying
you must have been skivvying
they must have been skivvying	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't skivvy
you mustn't skivvy
he mustn't skivvy
we mustn't skivvy
you mustn't skivvy
they mustn't skivvy 	I mustn't be skivvying
you mustn't be skivvying
he mustn't be skivvying
we mustn't be skivvying
you mustn't be skivvying
they mustn't be skivvying	I mustn't have skivvied
you mustn't have skivvied
he mustn't have skivvied
we mustn't have skivvied
you mustn't have skivvied
they mustn't have skivvied	I mustn't have been skivvying
you mustn't have been skivvying
he mustn't have been skivvying
we mustn't have been skivvying
you mustn't have been skivvying
they mustn't have been skivvying	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I skivvy?
must you skivvy?
must he skivvy?
must we skivvy?
must you skivvy?
must they skivvy? 	must I be skivvying?
must you be skivvying?
must he be skivvying?
must we be skivvying?
must you be skivvying?
must they be skivvying? 	must I have skivvied?
must you have skivvied?
must he have skivvied?
must we have skivvied?
must you have skivvied?
must they have skivvied? 	must I have been skivvying?
must you have been skivvying?
must he have been skivvying?
must we have been skivvying?
must you have been skivvying?
must they have been skivvying? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I skivvy?
mustn't you skivvy?
mustn't he skivvy?
mustn't we skivvy?
mustn't you skivvy?
mustn't they skivvy? 	mustn't I be skivvying?
mustn't you be skivvying?
mustn't he be skivvying?
mustn't we be skivvying?
mustn't you be skivvying?
mustn't they be skivvying? 	mustn't I have skivvied?
mustn't you have skivvied?
mustn't he have skivvied?
mustn't we have skivvied?
mustn't you have skivvied?
mustn't they have skivvied? 	mustn't I have been skivvying?
mustn't you have been skivvying?
mustn't he have been skivvying?
mustn't we have been skivvying?
mustn't you have been skivvying?
mustn't they have been skivvying?