must billow
Regular verb: billow - billowed- billowed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must billow
you must billow
she must billow
we must billow
you must billow
they must billow 	I must be billowing
you must be billowing
she must be billowing
we must be billowing
you must be billowing
they must be billowing	I must have billowed
you must have billowed
she must have billowed
we must have billowed
you must have billowed
they must have billowed	I must have been billowing
you must have been billowing
she must have been billowing
we must have been billowing
you must have been billowing
they must have been billowing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't billow
you mustn't billow
she mustn't billow
we mustn't billow
you mustn't billow
they mustn't billow 	I mustn't be billowing
you mustn't be billowing
she mustn't be billowing
we mustn't be billowing
you mustn't be billowing
they mustn't be billowing	I mustn't have billowed
you mustn't have billowed
she mustn't have billowed
we mustn't have billowed
you mustn't have billowed
they mustn't have billowed	I mustn't have been billowing
you mustn't have been billowing
she mustn't have been billowing
we mustn't have been billowing
you mustn't have been billowing
they mustn't have been billowing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I billow?
must you billow?
must she billow?
must we billow?
must you billow?
must they billow? 	must I be billowing?
must you be billowing?
must she be billowing?
must we be billowing?
must you be billowing?
must they be billowing? 	must I have billowed?
must you have billowed?
must she have billowed?
must we have billowed?
must you have billowed?
must they have billowed? 	must I have been billowing?
must you have been billowing?
must she have been billowing?
must we have been billowing?
must you have been billowing?
must they have been billowing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I billow?
mustn't you billow?
mustn't she billow?
mustn't we billow?
mustn't you billow?
mustn't they billow? 	mustn't I be billowing?
mustn't you be billowing?
mustn't she be billowing?
mustn't we be billowing?
mustn't you be billowing?
mustn't they be billowing? 	mustn't I have billowed?
mustn't you have billowed?
mustn't she have billowed?
mustn't we have billowed?
mustn't you have billowed?
mustn't they have billowed? 	mustn't I have been billowing?
mustn't you have been billowing?
mustn't she have been billowing?
mustn't we have been billowing?
mustn't you have been billowing?
mustn't they have been billowing?