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