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