must sun
Regular verb: sun - sunned- sunned

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must sun
you must sun
he must sun
we must sun
you must sun
they must sun 	I must be sunning
you must be sunning
he must be sunning
we must be sunning
you must be sunning
they must be sunning	I must have sunned
you must have sunned
he must have sunned
we must have sunned
you must have sunned
they must have sunned	I must have been sunning
you must have been sunning
he must have been sunning
we must have been sunning
you must have been sunning
they must have been sunning	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't sun
you mustn't sun
he mustn't sun
we mustn't sun
you mustn't sun
they mustn't sun 	I mustn't be sunning
you mustn't be sunning
he mustn't be sunning
we mustn't be sunning
you mustn't be sunning
they mustn't be sunning	I mustn't have sunned
you mustn't have sunned
he mustn't have sunned
we mustn't have sunned
you mustn't have sunned
they mustn't have sunned	I mustn't have been sunning
you mustn't have been sunning
he mustn't have been sunning
we mustn't have been sunning
you mustn't have been sunning
they mustn't have been sunning	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I sun?
must you sun?
must he sun?
must we sun?
must you sun?
must they sun? 	must I be sunning?
must you be sunning?
must he be sunning?
must we be sunning?
must you be sunning?
must they be sunning? 	must I have sunned?
must you have sunned?
must he have sunned?
must we have sunned?
must you have sunned?
must they have sunned? 	must I have been sunning?
must you have been sunning?
must he have been sunning?
must we have been sunning?
must you have been sunning?
must they have been sunning? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I sun?
mustn't you sun?
mustn't he sun?
mustn't we sun?
mustn't you sun?
mustn't they sun? 	mustn't I be sunning?
mustn't you be sunning?
mustn't he be sunning?
mustn't we be sunning?
mustn't you be sunning?
mustn't they be sunning? 	mustn't I have sunned?
mustn't you have sunned?
mustn't he have sunned?
mustn't we have sunned?
mustn't you have sunned?
mustn't they have sunned? 	mustn't I have been sunning?
mustn't you have been sunning?
mustn't he have been sunning?
mustn't we have been sunning?
mustn't you have been sunning?
mustn't they have been sunning?