I must prefix you must prefix she must prefix we must prefix you must prefix they must prefix
V-ing form
I must be prefixing you must be prefixing she must be prefixing we must be prefixing you must be prefixing they must be prefixing
Perfect
I must have prefixed you must have prefixed she must have prefixed we must have prefixed you must have prefixed they must have prefixed
V-ing perfect
I must have been prefixing you must have been prefixing she must have been prefixing we must have been prefixing you must have been prefixing they must have been prefixing
Negation
Simple form
I mustn't prefix you mustn't prefix she mustn't prefix we mustn't prefix you mustn't prefix they mustn't prefix
V-ing form
I mustn't be prefixing you mustn't be prefixing she mustn't be prefixing we mustn't be prefixing you mustn't be prefixing they mustn't be prefixing
Perfect
I mustn't have prefixed you mustn't have prefixed she mustn't have prefixed we mustn't have prefixed you mustn't have prefixed they mustn't have prefixed
V-ing perfect
I mustn't have been prefixing you mustn't have been prefixing she mustn't have been prefixing we mustn't have been prefixing you mustn't have been prefixing they mustn't have been prefixing
Interrogative form
Simple form
must I prefix? must you prefix? must she prefix? must we prefix? must you prefix? must they prefix?
V-ing form
must I be prefixing? must you be prefixing? must she be prefixing? must we be prefixing? must you be prefixing? must they be prefixing?
Perfect
must I have prefixed? must you have prefixed? must she have prefixed? must we have prefixed? must you have prefixed? must they have prefixed?
V-ing perfect
must I have been prefixing? must you have been prefixing? must she have been prefixing? must we have been prefixing? must you have been prefixing? must they have been prefixing?
Interro-negative form
Simple form
mustn't I prefix? mustn't you prefix? mustn't she prefix? mustn't we prefix? mustn't you prefix? mustn't they prefix?
V-ing form
mustn't I be prefixing? mustn't you be prefixing? mustn't she be prefixing? mustn't we be prefixing? mustn't you be prefixing? mustn't they be prefixing?
Perfect
mustn't I have prefixed? mustn't you have prefixed? mustn't she have prefixed? mustn't we have prefixed? mustn't you have prefixed? mustn't they have prefixed?
V-ing perfect
mustn't I have been prefixing? mustn't you have been prefixing? mustn't she have been prefixing? mustn't we have been prefixing? mustn't you have been prefixing? mustn't they have been prefixing?