must unchair
Regular verb: unchair - unchaired- unchaired

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must unchair
you must unchair
he must unchair
we must unchair
you must unchair
they must unchair 	I must be unchairing
you must be unchairing
he must be unchairing
we must be unchairing
you must be unchairing
they must be unchairing	I must have unchaired
you must have unchaired
he must have unchaired
we must have unchaired
you must have unchaired
they must have unchaired	I must have been unchairing
you must have been unchairing
he must have been unchairing
we must have been unchairing
you must have been unchairing
they must have been unchairing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't unchair
you mustn't unchair
he mustn't unchair
we mustn't unchair
you mustn't unchair
they mustn't unchair 	I mustn't be unchairing
you mustn't be unchairing
he mustn't be unchairing
we mustn't be unchairing
you mustn't be unchairing
they mustn't be unchairing	I mustn't have unchaired
you mustn't have unchaired
he mustn't have unchaired
we mustn't have unchaired
you mustn't have unchaired
they mustn't have unchaired	I mustn't have been unchairing
you mustn't have been unchairing
he mustn't have been unchairing
we mustn't have been unchairing
you mustn't have been unchairing
they mustn't have been unchairing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I unchair?
must you unchair?
must he unchair?
must we unchair?
must you unchair?
must they unchair? 	must I be unchairing?
must you be unchairing?
must he be unchairing?
must we be unchairing?
must you be unchairing?
must they be unchairing? 	must I have unchaired?
must you have unchaired?
must he have unchaired?
must we have unchaired?
must you have unchaired?
must they have unchaired? 	must I have been unchairing?
must you have been unchairing?
must he have been unchairing?
must we have been unchairing?
must you have been unchairing?
must they have been unchairing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I unchair?
mustn't you unchair?
mustn't he unchair?
mustn't we unchair?
mustn't you unchair?
mustn't they unchair? 	mustn't I be unchairing?
mustn't you be unchairing?
mustn't he be unchairing?
mustn't we be unchairing?
mustn't you be unchairing?
mustn't they be unchairing? 	mustn't I have unchaired?
mustn't you have unchaired?
mustn't he have unchaired?
mustn't we have unchaired?
mustn't you have unchaired?
mustn't they have unchaired? 	mustn't I have been unchairing?
mustn't you have been unchairing?
mustn't he have been unchairing?
mustn't we have been unchairing?
mustn't you have been unchairing?
mustn't they have been unchairing?