must deepen
Regular verb: deepen - deepened- deepened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must deepen
you must deepen
she must deepen
we must deepen
you must deepen
they must deepen 	I must be deepening
you must be deepening
she must be deepening
we must be deepening
you must be deepening
they must be deepening	I must have deepened
you must have deepened
she 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
she 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
she 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
she 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
she 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
she 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 she deepen?
must we deepen?
must you deepen?
must they deepen? 	must I be deepening?
must you be deepening?
must she be deepening?
must we be deepening?
must you be deepening?
must they be deepening? 	must I have deepened?
must you have deepened?
must she 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 she 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 she 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 she 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 she 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 she have been deepening?
mustn't we have been deepening?
mustn't you have been deepening?
mustn't they have been deepening?