Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I must cast off you must cast off she must cast off we must cast off you must cast off they must cast off
V-ing form
I must be cast offing you must be cast offing she must be cast offing we must be cast offing you must be cast offing they must be cast offing
Perfect
I must have cast offed you must have cast offed she must have cast offed we must have cast offed you must have cast offed they must have cast offed
V-ing perfect
I must have been cast offing you must have been cast offing she must have been cast offing we must have been cast offing you must have been cast offing they must have been cast offing
Negation
Simple form
I mustn't cast off you mustn't cast off she mustn't cast off we mustn't cast off you mustn't cast off they mustn't cast off
V-ing form
I mustn't be cast offing you mustn't be cast offing she mustn't be cast offing we mustn't be cast offing you mustn't be cast offing they mustn't be cast offing
Perfect
I mustn't have cast offed you mustn't have cast offed she mustn't have cast offed we mustn't have cast offed you mustn't have cast offed they mustn't have cast offed
V-ing perfect
I mustn't have been cast offing you mustn't have been cast offing she mustn't have been cast offing we mustn't have been cast offing you mustn't have been cast offing they mustn't have been cast offing
Interrogative form
Simple form
must I cast off? must you cast off? must she cast off? must we cast off? must you cast off? must they cast off?
V-ing form
must I be cast offing? must you be cast offing? must she be cast offing? must we be cast offing? must you be cast offing? must they be cast offing?
Perfect
must I have cast offed? must you have cast offed? must she have cast offed? must we have cast offed? must you have cast offed? must they have cast offed?
V-ing perfect
must I have been cast offing? must you have been cast offing? must she have been cast offing? must we have been cast offing? must you have been cast offing? must they have been cast offing?
Interro-negative form
Simple form
mustn't I cast off? mustn't you cast off? mustn't she cast off? mustn't we cast off? mustn't you cast off? mustn't they cast off?
V-ing form
mustn't I be cast offing? mustn't you be cast offing? mustn't she be cast offing? mustn't we be cast offing? mustn't you be cast offing? mustn't they be cast offing?
Perfect
mustn't I have cast offed? mustn't you have cast offed? mustn't she have cast offed? mustn't we have cast offed? mustn't you have cast offed? mustn't they have cast offed?
V-ing perfect
mustn't I have been cast offing? mustn't you have been cast offing? mustn't she have been cast offing? mustn't we have been cast offing? mustn't you have been cast offing? mustn't they have been cast offing?