must deepen
Regular verb: deepen - deepened- deepened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must deepen
you must deepen
he must deepen
we must deepen
you must deepen
they must deepen 	I must be deepening
you must be deepening
he must be deepening
we must be deepening
you must be deepening
they must be deepening	I must have deepened
you must have deepened
he must have deepened
we must have deepened
you must have deepened
they must have deepened	I must have been deepening
you must have been deepening
he must have been deepening
we must have been deepening
you must have been deepening
they must have been deepening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't deepen
you mustn't deepen
he mustn't deepen
we mustn't deepen
you mustn't deepen
they mustn't deepen 	I mustn't be deepening
you mustn't be deepening
he mustn't be deepening
we mustn't be deepening
you mustn't be deepening
they mustn't be deepening	I mustn't have deepened
you mustn't have deepened
he mustn't have deepened
we mustn't have deepened
you mustn't have deepened
they mustn't have deepened	I mustn't have been deepening
you mustn't have been deepening
he mustn't have been deepening
we mustn't have been deepening
you mustn't have been deepening
they mustn't have been deepening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I deepen?
must you deepen?
must he deepen?
must we deepen?
must you deepen?
must they deepen? 	must I be deepening?
must you be deepening?
must he be deepening?
must we be deepening?
must you be deepening?
must they be deepening? 	must I have deepened?
must you have deepened?
must he have deepened?
must we have deepened?
must you have deepened?
must they have deepened? 	must I have been deepening?
must you have been deepening?
must he have been deepening?
must we have been deepening?
must you have been deepening?
must they have been deepening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I deepen?
mustn't you deepen?
mustn't he deepen?
mustn't we deepen?
mustn't you deepen?
mustn't they deepen? 	mustn't I be deepening?
mustn't you be deepening?
mustn't he be deepening?
mustn't we be deepening?
mustn't you be deepening?
mustn't they be deepening? 	mustn't I have deepened?
mustn't you have deepened?
mustn't he have deepened?
mustn't we have deepened?
mustn't you have deepened?
mustn't they have deepened? 	mustn't I have been deepening?
mustn't you have been deepening?
mustn't he have been deepening?
mustn't we have been deepening?
mustn't you have been deepening?
mustn't they have been deepening?