must rebut
Regular verb: rebut - rebuted- rebuted

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must rebut
you must rebut
he must rebut
we must rebut
you must rebut
they must rebut 	I must be rebuting
you must be rebuting
he must be rebuting
we must be rebuting
you must be rebuting
they must be rebuting	I must have rebuted
you must have rebuted
he must have rebuted
we must have rebuted
you must have rebuted
they must have rebuted	I must have been rebuting
you must have been rebuting
he must have been rebuting
we must have been rebuting
you must have been rebuting
they must have been rebuting	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't rebut
you mustn't rebut
he mustn't rebut
we mustn't rebut
you mustn't rebut
they mustn't rebut 	I mustn't be rebuting
you mustn't be rebuting
he mustn't be rebuting
we mustn't be rebuting
you mustn't be rebuting
they mustn't be rebuting	I mustn't have rebuted
you mustn't have rebuted
he mustn't have rebuted
we mustn't have rebuted
you mustn't have rebuted
they mustn't have rebuted	I mustn't have been rebuting
you mustn't have been rebuting
he mustn't have been rebuting
we mustn't have been rebuting
you mustn't have been rebuting
they mustn't have been rebuting	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I rebut?
must you rebut?
must he rebut?
must we rebut?
must you rebut?
must they rebut? 	must I be rebuting?
must you be rebuting?
must he be rebuting?
must we be rebuting?
must you be rebuting?
must they be rebuting? 	must I have rebuted?
must you have rebuted?
must he have rebuted?
must we have rebuted?
must you have rebuted?
must they have rebuted? 	must I have been rebuting?
must you have been rebuting?
must he have been rebuting?
must we have been rebuting?
must you have been rebuting?
must they have been rebuting? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I rebut?
mustn't you rebut?
mustn't he rebut?
mustn't we rebut?
mustn't you rebut?
mustn't they rebut? 	mustn't I be rebuting?
mustn't you be rebuting?
mustn't he be rebuting?
mustn't we be rebuting?
mustn't you be rebuting?
mustn't they be rebuting? 	mustn't I have rebuted?
mustn't you have rebuted?
mustn't he have rebuted?
mustn't we have rebuted?
mustn't you have rebuted?
mustn't they have rebuted? 	mustn't I have been rebuting?
mustn't you have been rebuting?
mustn't he have been rebuting?
mustn't we have been rebuting?
mustn't you have been rebuting?
mustn't they have been rebuting?