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