I must enter you must enter he must enter we must enter you must enter they must enter
V-ing form
I must be entering you must be entering he must be entering we must be entering you must be entering they must be entering
Perfect
I must have entered you must have entered he must have entered we must have entered you must have entered they must have entered
V-ing perfect
I must have been entering you must have been entering he must have been entering we must have been entering you must have been entering they must have been entering
Negation
Simple form
I mustn't enter you mustn't enter he mustn't enter we mustn't enter you mustn't enter they mustn't enter
V-ing form
I mustn't be entering you mustn't be entering he mustn't be entering we mustn't be entering you mustn't be entering they mustn't be entering
Perfect
I mustn't have entered you mustn't have entered he mustn't have entered we mustn't have entered you mustn't have entered they mustn't have entered
V-ing perfect
I mustn't have been entering you mustn't have been entering he mustn't have been entering we mustn't have been entering you mustn't have been entering they mustn't have been entering
Interrogative form
Simple form
must I enter? must you enter? must he enter? must we enter? must you enter? must they enter?
V-ing form
must I be entering? must you be entering? must he be entering? must we be entering? must you be entering? must they be entering?
Perfect
must I have entered? must you have entered? must he have entered? must we have entered? must you have entered? must they have entered?
V-ing perfect
must I have been entering? must you have been entering? must he have been entering? must we have been entering? must you have been entering? must they have been entering?
Interro-negative form
Simple form
mustn't I enter? mustn't you enter? mustn't he enter? mustn't we enter? mustn't you enter? mustn't they enter?
V-ing form
mustn't I be entering? mustn't you be entering? mustn't he be entering? mustn't we be entering? mustn't you be entering? mustn't they be entering?
Perfect
mustn't I have entered? mustn't you have entered? mustn't he have entered? mustn't we have entered? mustn't you have entered? mustn't they have entered?
V-ing perfect
mustn't I have been entering? mustn't you have been entering? mustn't he have been entering? mustn't we have been entering? mustn't you have been entering? mustn't they have been entering?