I must brush you must brush she must brush we must brush you must brush they must brush
V-ing form
I must be brushing you must be brushing she must be brushing we must be brushing you must be brushing they must be brushing
Perfect
I must have brushed you must have brushed she must have brushed we must have brushed you must have brushed they must have brushed
V-ing perfect
I must have been brushing you must have been brushing she must have been brushing we must have been brushing you must have been brushing they must have been brushing
Negation
Simple form
I must not brush you must not brush she must not brush we must not brush you must not brush they must not brush
V-ing form
I must not be brushing you must not be brushing she must not be brushing we must not be brushing you must not be brushing they must not be brushing
Perfect
I must not have brushed you must not have brushed she must not have brushed we must not have brushed you must not have brushed they must not have brushed
V-ing perfect
I must not have been brushing you must not have been brushing she must not have been brushing we must not have been brushing you must not have been brushing they must not have been brushing
Interrogative form
Simple form
must I brush? must you brush? must she brush? must we brush? must you brush? must they brush?
V-ing form
must I be brushing? must you be brushing? must she be brushing? must we be brushing? must you be brushing? must they be brushing?
Perfect
must I have brushed? must you have brushed? must she have brushed? must we have brushed? must you have brushed? must they have brushed?
V-ing perfect
must I have been brushing? must you have been brushing? must she have been brushing? must we have been brushing? must you have been brushing? must they have been brushing?
Interro-negative form
Simple form
must I not brush? must you not brush? must she not brush? must we not brush? must you not brush? must they not brush?
V-ing form
must I not be brushing? must you not be brushing? must she not be brushing? must we not be brushing? must you not be brushing? must they not be brushing?
Perfect
must I not have brushed? must you not have brushed? must she not have brushed? must we not have brushed? must you not have brushed? must they not have brushed?
V-ing perfect
must I not have been brushing? must you not have been brushing? must she not have been brushing? must we not have been brushing? must you not have been brushing? must they not have been brushing?