must sub
Regular verb: sub - subbed- subbed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must sub
you must sub
he must sub
we must sub
you must sub
they must sub 	I must be subbing
you must be subbing
he must be subbing
we must be subbing
you must be subbing
they must be subbing	I must have subbed
you must have subbed
he must have subbed
we must have subbed
you must have subbed
they must have subbed	I must have been subbing
you must have been subbing
he must have been subbing
we must have been subbing
you must have been subbing
they must have been subbing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't sub
you mustn't sub
he mustn't sub
we mustn't sub
you mustn't sub
they mustn't sub 	I mustn't be subbing
you mustn't be subbing
he mustn't be subbing
we mustn't be subbing
you mustn't be subbing
they mustn't be subbing	I mustn't have subbed
you mustn't have subbed
he mustn't have subbed
we mustn't have subbed
you mustn't have subbed
they mustn't have subbed	I mustn't have been subbing
you mustn't have been subbing
he mustn't have been subbing
we mustn't have been subbing
you mustn't have been subbing
they mustn't have been subbing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I sub?
must you sub?
must he sub?
must we sub?
must you sub?
must they sub? 	must I be subbing?
must you be subbing?
must he be subbing?
must we be subbing?
must you be subbing?
must they be subbing? 	must I have subbed?
must you have subbed?
must he have subbed?
must we have subbed?
must you have subbed?
must they have subbed? 	must I have been subbing?
must you have been subbing?
must he have been subbing?
must we have been subbing?
must you have been subbing?
must they have been subbing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I sub?
mustn't you sub?
mustn't he sub?
mustn't we sub?
mustn't you sub?
mustn't they sub? 	mustn't I be subbing?
mustn't you be subbing?
mustn't he be subbing?
mustn't we be subbing?
mustn't you be subbing?
mustn't they be subbing? 	mustn't I have subbed?
mustn't you have subbed?
mustn't he have subbed?
mustn't we have subbed?
mustn't you have subbed?
mustn't they have subbed? 	mustn't I have been subbing?
mustn't you have been subbing?
mustn't he have been subbing?
mustn't we have been subbing?
mustn't you have been subbing?
mustn't they have been subbing?