must fable
Regular verb: fable - fabled- fabled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must fable
you must fable
he must fable
we must fable
you must fable
they must fable 	I must be fabling
you must be fabling
he must be fabling
we must be fabling
you must be fabling
they must be fabling	I must have fabled
you must have fabled
he must have fabled
we must have fabled
you must have fabled
they must have fabled	I must have been fabling
you must have been fabling
he must have been fabling
we must have been fabling
you must have been fabling
they must have been fabling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not fable
you must not fable
he must not fable
we must not fable
you must not fable
they must not fable 	I must not be fabling
you must not be fabling
he must not be fabling
we must not be fabling
you must not be fabling
they must not be fabling	I must not have fabled
you must not have fabled
he must not have fabled
we must not have fabled
you must not have fabled
they must not have fabled	I must not have been fabling
you must not have been fabling
he must not have been fabling
we must not have been fabling
you must not have been fabling
they must not have been fabling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I fable?
must you fable?
must he fable?
must we fable?
must you fable?
must they fable? 	must I be fabling?
must you be fabling?
must he be fabling?
must we be fabling?
must you be fabling?
must they be fabling? 	must I have fabled?
must you have fabled?
must he have fabled?
must we have fabled?
must you have fabled?
must they have fabled? 	must I have been fabling?
must you have been fabling?
must he have been fabling?
must we have been fabling?
must you have been fabling?
must they have been fabling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not fable?
must you not fable?
must he not fable?
must we not fable?
must you not fable?
must they not fable? 	must I not be fabling?
must you not be fabling?
must he not be fabling?
must we not be fabling?
must you not be fabling?
must they not be fabling? 	must I not have fabled?
must you not have fabled?
must he not have fabled?
must we not have fabled?
must you not have fabled?
must they not have fabled? 	must I not have been fabling?
must you not have been fabling?
must he not have been fabling?
must we not have been fabling?
must you not have been fabling?
must they not have been fabling?