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