I must fever you must fever he must fever we must fever you must fever they must fever
V-ing form
I must be fevering you must be fevering he must be fevering we must be fevering you must be fevering they must be fevering
Perfect
I must have fevered you must have fevered he must have fevered we must have fevered you must have fevered they must have fevered
V-ing perfect
I must have been fevering you must have been fevering he must have been fevering we must have been fevering you must have been fevering they must have been fevering
Negation
Simple form
I must not fever you must not fever he must not fever we must not fever you must not fever they must not fever
V-ing form
I must not be fevering you must not be fevering he must not be fevering we must not be fevering you must not be fevering they must not be fevering
Perfect
I must not have fevered you must not have fevered he must not have fevered we must not have fevered you must not have fevered they must not have fevered
V-ing perfect
I must not have been fevering you must not have been fevering he must not have been fevering we must not have been fevering you must not have been fevering they must not have been fevering
Interrogative form
Simple form
must I fever? must you fever? must he fever? must we fever? must you fever? must they fever?
V-ing form
must I be fevering? must you be fevering? must he be fevering? must we be fevering? must you be fevering? must they be fevering?
Perfect
must I have fevered? must you have fevered? must he have fevered? must we have fevered? must you have fevered? must they have fevered?
V-ing perfect
must I have been fevering? must you have been fevering? must he have been fevering? must we have been fevering? must you have been fevering? must they have been fevering?
Interro-negative form
Simple form
must I not fever? must you not fever? must he not fever? must we not fever? must you not fever? must they not fever?
V-ing form
must I not be fevering? must you not be fevering? must he not be fevering? must we not be fevering? must you not be fevering? must they not be fevering?
Perfect
must I not have fevered? must you not have fevered? must he not have fevered? must we not have fevered? must you not have fevered? must they not have fevered?
V-ing perfect
must I not have been fevering? must you not have been fevering? must he not have been fevering? must we not have been fevering? must you not have been fevering? must they not have been fevering?