must callus
Regular verb: callus - callused- callused

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must callus
you must callus
he must callus
we must callus
you must callus
they must callus 	I must be callusing
you must be callusing
he must be callusing
we must be callusing
you must be callusing
they must be callusing	I must have callused
you must have callused
he must have callused
we must have callused
you must have callused
they must have callused	I must have been callusing
you must have been callusing
he must have been callusing
we must have been callusing
you must have been callusing
they must have been callusing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not callus
you must not callus
he must not callus
we must not callus
you must not callus
they must not callus 	I must not be callusing
you must not be callusing
he must not be callusing
we must not be callusing
you must not be callusing
they must not be callusing	I must not have callused
you must not have callused
he must not have callused
we must not have callused
you must not have callused
they must not have callused	I must not have been callusing
you must not have been callusing
he must not have been callusing
we must not have been callusing
you must not have been callusing
they must not have been callusing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I callus?
must you callus?
must he callus?
must we callus?
must you callus?
must they callus? 	must I be callusing?
must you be callusing?
must he be callusing?
must we be callusing?
must you be callusing?
must they be callusing? 	must I have callused?
must you have callused?
must he have callused?
must we have callused?
must you have callused?
must they have callused? 	must I have been callusing?
must you have been callusing?
must he have been callusing?
must we have been callusing?
must you have been callusing?
must they have been callusing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not callus?
must you not callus?
must he not callus?
must we not callus?
must you not callus?
must they not callus? 	must I not be callusing?
must you not be callusing?
must he not be callusing?
must we not be callusing?
must you not be callusing?
must they not be callusing? 	must I not have callused?
must you not have callused?
must he not have callused?
must we not have callused?
must you not have callused?
must they not have callused? 	must I not have been callusing?
must you not have been callusing?
must he not have been callusing?
must we not have been callusing?
must you not have been callusing?
must they not have been callusing?