must dampen
Regular verb: dampen - dampened- dampened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must dampen
you must dampen
he must dampen
we must dampen
you must dampen
they must dampen 	I must be dampening
you must be dampening
he must be dampening
we must be dampening
you must be dampening
they must be dampening	I must have dampened
you must have dampened
he must have dampened
we must have dampened
you must have dampened
they must have dampened	I must have been dampening
you must have been dampening
he must have been dampening
we must have been dampening
you must have been dampening
they must have been dampening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't dampen
you mustn't dampen
he mustn't dampen
we mustn't dampen
you mustn't dampen
they mustn't dampen 	I mustn't be dampening
you mustn't be dampening
he mustn't be dampening
we mustn't be dampening
you mustn't be dampening
they mustn't be dampening	I mustn't have dampened
you mustn't have dampened
he mustn't have dampened
we mustn't have dampened
you mustn't have dampened
they mustn't have dampened	I mustn't have been dampening
you mustn't have been dampening
he mustn't have been dampening
we mustn't have been dampening
you mustn't have been dampening
they mustn't have been dampening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I dampen?
must you dampen?
must he dampen?
must we dampen?
must you dampen?
must they dampen? 	must I be dampening?
must you be dampening?
must he be dampening?
must we be dampening?
must you be dampening?
must they be dampening? 	must I have dampened?
must you have dampened?
must he have dampened?
must we have dampened?
must you have dampened?
must they have dampened? 	must I have been dampening?
must you have been dampening?
must he have been dampening?
must we have been dampening?
must you have been dampening?
must they have been dampening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I dampen?
mustn't you dampen?
mustn't he dampen?
mustn't we dampen?
mustn't you dampen?
mustn't they dampen? 	mustn't I be dampening?
mustn't you be dampening?
mustn't he be dampening?
mustn't we be dampening?
mustn't you be dampening?
mustn't they be dampening? 	mustn't I have dampened?
mustn't you have dampened?
mustn't he have dampened?
mustn't we have dampened?
mustn't you have dampened?
mustn't they have dampened? 	mustn't I have been dampening?
mustn't you have been dampening?
mustn't he have been dampening?
mustn't we have been dampening?
mustn't you have been dampening?
mustn't they have been dampening?