must undulate
Regular verb: undulate - undulated- undulated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must undulate
you must undulate
he must undulate
we must undulate
you must undulate
they must undulate 	I must be undulating
you must be undulating
he must be undulating
we must be undulating
you must be undulating
they must be undulating	I must have undulated
you must have undulated
he must have undulated
we must have undulated
you must have undulated
they must have undulated	I must have been undulating
you must have been undulating
he must have been undulating
we must have been undulating
you must have been undulating
they must have been undulating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't undulate
you mustn't undulate
he mustn't undulate
we mustn't undulate
you mustn't undulate
they mustn't undulate 	I mustn't be undulating
you mustn't be undulating
he mustn't be undulating
we mustn't be undulating
you mustn't be undulating
they mustn't be undulating	I mustn't have undulated
you mustn't have undulated
he mustn't have undulated
we mustn't have undulated
you mustn't have undulated
they mustn't have undulated	I mustn't have been undulating
you mustn't have been undulating
he mustn't have been undulating
we mustn't have been undulating
you mustn't have been undulating
they mustn't have been undulating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I undulate?
must you undulate?
must he undulate?
must we undulate?
must you undulate?
must they undulate? 	must I be undulating?
must you be undulating?
must he be undulating?
must we be undulating?
must you be undulating?
must they be undulating? 	must I have undulated?
must you have undulated?
must he have undulated?
must we have undulated?
must you have undulated?
must they have undulated? 	must I have been undulating?
must you have been undulating?
must he have been undulating?
must we have been undulating?
must you have been undulating?
must they have been undulating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I undulate?
mustn't you undulate?
mustn't he undulate?
mustn't we undulate?
mustn't you undulate?
mustn't they undulate? 	mustn't I be undulating?
mustn't you be undulating?
mustn't he be undulating?
mustn't we be undulating?
mustn't you be undulating?
mustn't they be undulating? 	mustn't I have undulated?
mustn't you have undulated?
mustn't he have undulated?
mustn't we have undulated?
mustn't you have undulated?
mustn't they have undulated? 	mustn't I have been undulating?
mustn't you have been undulating?
mustn't he have been undulating?
mustn't we have been undulating?
mustn't you have been undulating?
mustn't they have been undulating?