must snack
Regular verb: snack - snacked- snacked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must snack
you must snack
he must snack
we must snack
you must snack
they must snack 	I must be snacking
you must be snacking
he must be snacking
we must be snacking
you must be snacking
they must be snacking	I must have snacked
you must have snacked
he must have snacked
we must have snacked
you must have snacked
they must have snacked	I must have been snacking
you must have been snacking
he must have been snacking
we must have been snacking
you must have been snacking
they must have been snacking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't snack
you mustn't snack
he mustn't snack
we mustn't snack
you mustn't snack
they mustn't snack 	I mustn't be snacking
you mustn't be snacking
he mustn't be snacking
we mustn't be snacking
you mustn't be snacking
they mustn't be snacking	I mustn't have snacked
you mustn't have snacked
he mustn't have snacked
we mustn't have snacked
you mustn't have snacked
they mustn't have snacked	I mustn't have been snacking
you mustn't have been snacking
he mustn't have been snacking
we mustn't have been snacking
you mustn't have been snacking
they mustn't have been snacking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I snack?
must you snack?
must he snack?
must we snack?
must you snack?
must they snack? 	must I be snacking?
must you be snacking?
must he be snacking?
must we be snacking?
must you be snacking?
must they be snacking? 	must I have snacked?
must you have snacked?
must he have snacked?
must we have snacked?
must you have snacked?
must they have snacked? 	must I have been snacking?
must you have been snacking?
must he have been snacking?
must we have been snacking?
must you have been snacking?
must they have been snacking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I snack?
mustn't you snack?
mustn't he snack?
mustn't we snack?
mustn't you snack?
mustn't they snack? 	mustn't I be snacking?
mustn't you be snacking?
mustn't he be snacking?
mustn't we be snacking?
mustn't you be snacking?
mustn't they be snacking? 	mustn't I have snacked?
mustn't you have snacked?
mustn't he have snacked?
mustn't we have snacked?
mustn't you have snacked?
mustn't they have snacked? 	mustn't I have been snacking?
mustn't you have been snacking?
mustn't he have been snacking?
mustn't we have been snacking?
mustn't you have been snacking?
mustn't they have been snacking?