must sass
Regular verb: sass - sassed- sassed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must sass
you must sass
he must sass
we must sass
you must sass
they must sass 	I must be sassing
you must be sassing
he must be sassing
we must be sassing
you must be sassing
they must be sassing	I must have sassed
you must have sassed
he must have sassed
we must have sassed
you must have sassed
they must have sassed	I must have been sassing
you must have been sassing
he must have been sassing
we must have been sassing
you must have been sassing
they must have been sassing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't sass
you mustn't sass
he mustn't sass
we mustn't sass
you mustn't sass
they mustn't sass 	I mustn't be sassing
you mustn't be sassing
he mustn't be sassing
we mustn't be sassing
you mustn't be sassing
they mustn't be sassing	I mustn't have sassed
you mustn't have sassed
he mustn't have sassed
we mustn't have sassed
you mustn't have sassed
they mustn't have sassed	I mustn't have been sassing
you mustn't have been sassing
he mustn't have been sassing
we mustn't have been sassing
you mustn't have been sassing
they mustn't have been sassing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I sass?
must you sass?
must he sass?
must we sass?
must you sass?
must they sass? 	must I be sassing?
must you be sassing?
must he be sassing?
must we be sassing?
must you be sassing?
must they be sassing? 	must I have sassed?
must you have sassed?
must he have sassed?
must we have sassed?
must you have sassed?
must they have sassed? 	must I have been sassing?
must you have been sassing?
must he have been sassing?
must we have been sassing?
must you have been sassing?
must they have been sassing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I sass?
mustn't you sass?
mustn't he sass?
mustn't we sass?
mustn't you sass?
mustn't they sass? 	mustn't I be sassing?
mustn't you be sassing?
mustn't he be sassing?
mustn't we be sassing?
mustn't you be sassing?
mustn't they be sassing? 	mustn't I have sassed?
mustn't you have sassed?
mustn't he have sassed?
mustn't we have sassed?
mustn't you have sassed?
mustn't they have sassed? 	mustn't I have been sassing?
mustn't you have been sassing?
mustn't he have been sassing?
mustn't we have been sassing?
mustn't you have been sassing?
mustn't they have been sassing?