I must gag you must gag she must gag we must gag you must gag they must gag
V-ing form
I must be gagging you must be gagging she must be gagging we must be gagging you must be gagging they must be gagging
Perfect
I must have gagged you must have gagged she must have gagged we must have gagged you must have gagged they must have gagged
V-ing perfect
I must have been gagging you must have been gagging she must have been gagging we must have been gagging you must have been gagging they must have been gagging
Negation
Simple form
I must not gag you must not gag she must not gag we must not gag you must not gag they must not gag
V-ing form
I must not be gagging you must not be gagging she must not be gagging we must not be gagging you must not be gagging they must not be gagging
Perfect
I must not have gagged you must not have gagged she must not have gagged we must not have gagged you must not have gagged they must not have gagged
V-ing perfect
I must not have been gagging you must not have been gagging she must not have been gagging we must not have been gagging you must not have been gagging they must not have been gagging
Interrogative form
Simple form
must I gag? must you gag? must she gag? must we gag? must you gag? must they gag?
V-ing form
must I be gagging? must you be gagging? must she be gagging? must we be gagging? must you be gagging? must they be gagging?
Perfect
must I have gagged? must you have gagged? must she have gagged? must we have gagged? must you have gagged? must they have gagged?
V-ing perfect
must I have been gagging? must you have been gagging? must she have been gagging? must we have been gagging? must you have been gagging? must they have been gagging?
Interro-negative form
Simple form
must I not gag? must you not gag? must she not gag? must we not gag? must you not gag? must they not gag?
V-ing form
must I not be gagging? must you not be gagging? must she not be gagging? must we not be gagging? must you not be gagging? must they not be gagging?
Perfect
must I not have gagged? must you not have gagged? must she not have gagged? must we not have gagged? must you not have gagged? must they not have gagged?
V-ing perfect
must I not have been gagging? must you not have been gagging? must she not have been gagging? must we not have been gagging? must you not have been gagging? must they not have been gagging?