must comb
Regular verb: comb - combed- combed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must comb
you must comb
he must comb
we must comb
you must comb
they must comb 	I must be combing
you must be combing
he must be combing
we must be combing
you must be combing
they must be combing	I must have combed
you must have combed
he must have combed
we must have combed
you must have combed
they must have combed	I must have been combing
you must have been combing
he must have been combing
we must have been combing
you must have been combing
they must have been combing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not comb
you must not comb
he must not comb
we must not comb
you must not comb
they must not comb 	I must not be combing
you must not be combing
he must not be combing
we must not be combing
you must not be combing
they must not be combing	I must not have combed
you must not have combed
he must not have combed
we must not have combed
you must not have combed
they must not have combed	I must not have been combing
you must not have been combing
he must not have been combing
we must not have been combing
you must not have been combing
they must not have been combing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I comb?
must you comb?
must he comb?
must we comb?
must you comb?
must they comb? 	must I be combing?
must you be combing?
must he be combing?
must we be combing?
must you be combing?
must they be combing? 	must I have combed?
must you have combed?
must he have combed?
must we have combed?
must you have combed?
must they have combed? 	must I have been combing?
must you have been combing?
must he have been combing?
must we have been combing?
must you have been combing?
must they have been combing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not comb?
must you not comb?
must he not comb?
must we not comb?
must you not comb?
must they not comb? 	must I not be combing?
must you not be combing?
must he not be combing?
must we not be combing?
must you not be combing?
must they not be combing? 	must I not have combed?
must you not have combed?
must he not have combed?
must we not have combed?
must you not have combed?
must they not have combed? 	must I not have been combing?
must you not have been combing?
must he not have been combing?
must we not have been combing?
must you not have been combing?
must they not have been combing?