I must snap you must snap she must snap we must snap you must snap they must snap
V-ing form
I must be snapping you must be snapping she must be snapping we must be snapping you must be snapping they must be snapping
Perfect
I must have snapped you must have snapped she must have snapped we must have snapped you must have snapped they must have snapped
V-ing perfect
I must have been snapping you must have been snapping she must have been snapping we must have been snapping you must have been snapping they must have been snapping
Negation
Simple form
I must not snap you must not snap she must not snap we must not snap you must not snap they must not snap
V-ing form
I must not be snapping you must not be snapping she must not be snapping we must not be snapping you must not be snapping they must not be snapping
Perfect
I must not have snapped you must not have snapped she must not have snapped we must not have snapped you must not have snapped they must not have snapped
V-ing perfect
I must not have been snapping you must not have been snapping she must not have been snapping we must not have been snapping you must not have been snapping they must not have been snapping
Interrogative form
Simple form
must I snap? must you snap? must she snap? must we snap? must you snap? must they snap?
V-ing form
must I be snapping? must you be snapping? must she be snapping? must we be snapping? must you be snapping? must they be snapping?
Perfect
must I have snapped? must you have snapped? must she have snapped? must we have snapped? must you have snapped? must they have snapped?
V-ing perfect
must I have been snapping? must you have been snapping? must she have been snapping? must we have been snapping? must you have been snapping? must they have been snapping?
Interro-negative form
Simple form
must I not snap? must you not snap? must she not snap? must we not snap? must you not snap? must they not snap?
V-ing form
must I not be snapping? must you not be snapping? must she not be snapping? must we not be snapping? must you not be snapping? must they not be snapping?
Perfect
must I not have snapped? must you not have snapped? must she not have snapped? must we not have snapped? must you not have snapped? must they not have snapped?
V-ing perfect
must I not have been snapping? must you not have been snapping? must she not have been snapping? must we not have been snapping? must you not have been snapping? must they not have been snapping?