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