must soften
Regular verb: soften - softened- softened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must soften
you must soften
he must soften
we must soften
you must soften
they must soften 	I must be softening
you must be softening
he must be softening
we must be softening
you must be softening
they must be softening	I must have softened
you must have softened
he must have softened
we must have softened
you must have softened
they must have softened	I must have been softening
you must have been softening
he must have been softening
we must have been softening
you must have been softening
they must have been softening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't soften
you mustn't soften
he mustn't soften
we mustn't soften
you mustn't soften
they mustn't soften 	I mustn't be softening
you mustn't be softening
he mustn't be softening
we mustn't be softening
you mustn't be softening
they mustn't be softening	I mustn't have softened
you mustn't have softened
he mustn't have softened
we mustn't have softened
you mustn't have softened
they mustn't have softened	I mustn't have been softening
you mustn't have been softening
he mustn't have been softening
we mustn't have been softening
you mustn't have been softening
they mustn't have been softening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I soften?
must you soften?
must he soften?
must we soften?
must you soften?
must they soften? 	must I be softening?
must you be softening?
must he be softening?
must we be softening?
must you be softening?
must they be softening? 	must I have softened?
must you have softened?
must he have softened?
must we have softened?
must you have softened?
must they have softened? 	must I have been softening?
must you have been softening?
must he have been softening?
must we have been softening?
must you have been softening?
must they have been softening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I soften?
mustn't you soften?
mustn't he soften?
mustn't we soften?
mustn't you soften?
mustn't they soften? 	mustn't I be softening?
mustn't you be softening?
mustn't he be softening?
mustn't we be softening?
mustn't you be softening?
mustn't they be softening? 	mustn't I have softened?
mustn't you have softened?
mustn't he have softened?
mustn't we have softened?
mustn't you have softened?
mustn't they have softened? 	mustn't I have been softening?
mustn't you have been softening?
mustn't he have been softening?
mustn't we have been softening?
mustn't you have been softening?
mustn't they have been softening?