must penetrate
Regular verb: penetrate - penetrated- penetrated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must penetrate
you must penetrate
he must penetrate
we must penetrate
you must penetrate
they must penetrate 	I must be penetrating
you must be penetrating
he must be penetrating
we must be penetrating
you must be penetrating
they must be penetrating	I must have penetrated
you must have penetrated
he must have penetrated
we must have penetrated
you must have penetrated
they must have penetrated	I must have been penetrating
you must have been penetrating
he must have been penetrating
we must have been penetrating
you must have been penetrating
they must have been penetrating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't penetrate
you mustn't penetrate
he mustn't penetrate
we mustn't penetrate
you mustn't penetrate
they mustn't penetrate 	I mustn't be penetrating
you mustn't be penetrating
he mustn't be penetrating
we mustn't be penetrating
you mustn't be penetrating
they mustn't be penetrating	I mustn't have penetrated
you mustn't have penetrated
he mustn't have penetrated
we mustn't have penetrated
you mustn't have penetrated
they mustn't have penetrated	I mustn't have been penetrating
you mustn't have been penetrating
he mustn't have been penetrating
we mustn't have been penetrating
you mustn't have been penetrating
they mustn't have been penetrating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I penetrate?
must you penetrate?
must he penetrate?
must we penetrate?
must you penetrate?
must they penetrate? 	must I be penetrating?
must you be penetrating?
must he be penetrating?
must we be penetrating?
must you be penetrating?
must they be penetrating? 	must I have penetrated?
must you have penetrated?
must he have penetrated?
must we have penetrated?
must you have penetrated?
must they have penetrated? 	must I have been penetrating?
must you have been penetrating?
must he have been penetrating?
must we have been penetrating?
must you have been penetrating?
must they have been penetrating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I penetrate?
mustn't you penetrate?
mustn't he penetrate?
mustn't we penetrate?
mustn't you penetrate?
mustn't they penetrate? 	mustn't I be penetrating?
mustn't you be penetrating?
mustn't he be penetrating?
mustn't we be penetrating?
mustn't you be penetrating?
mustn't they be penetrating? 	mustn't I have penetrated?
mustn't you have penetrated?
mustn't he have penetrated?
mustn't we have penetrated?
mustn't you have penetrated?
mustn't they have penetrated? 	mustn't I have been penetrating?
mustn't you have been penetrating?
mustn't he have been penetrating?
mustn't we have been penetrating?
mustn't you have been penetrating?
mustn't they have been penetrating?