must snicker
Regular verb: snicker - snickered- snickered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must snicker
you must snicker
she must snicker
we must snicker
you must snicker
they must snicker 	I must be snickering
you must be snickering
she must be snickering
we must be snickering
you must be snickering
they must be snickering	I must have snickered
you must have snickered
she must have snickered
we must have snickered
you must have snickered
they must have snickered	I must have been snickering
you must have been snickering
she must have been snickering
we must have been snickering
you must have been snickering
they must have been snickering	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't snicker
you mustn't snicker
she mustn't snicker
we mustn't snicker
you mustn't snicker
they mustn't snicker 	I mustn't be snickering
you mustn't be snickering
she mustn't be snickering
we mustn't be snickering
you mustn't be snickering
they mustn't be snickering	I mustn't have snickered
you mustn't have snickered
she mustn't have snickered
we mustn't have snickered
you mustn't have snickered
they mustn't have snickered	I mustn't have been snickering
you mustn't have been snickering
she mustn't have been snickering
we mustn't have been snickering
you mustn't have been snickering
they mustn't have been snickering	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I snicker?
must you snicker?
must she snicker?
must we snicker?
must you snicker?
must they snicker? 	must I be snickering?
must you be snickering?
must she be snickering?
must we be snickering?
must you be snickering?
must they be snickering? 	must I have snickered?
must you have snickered?
must she have snickered?
must we have snickered?
must you have snickered?
must they have snickered? 	must I have been snickering?
must you have been snickering?
must she have been snickering?
must we have been snickering?
must you have been snickering?
must they have been snickering? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I snicker?
mustn't you snicker?
mustn't she snicker?
mustn't we snicker?
mustn't you snicker?
mustn't they snicker? 	mustn't I be snickering?
mustn't you be snickering?
mustn't she be snickering?
mustn't we be snickering?
mustn't you be snickering?
mustn't they be snickering? 	mustn't I have snickered?
mustn't you have snickered?
mustn't she have snickered?
mustn't we have snickered?
mustn't you have snickered?
mustn't they have snickered? 	mustn't I have been snickering?
mustn't you have been snickering?
mustn't she have been snickering?
mustn't we have been snickering?
mustn't you have been snickering?
mustn't they have been snickering?