I must while you must while she must while we must while you must while they must while
V-ing form
I must be whiling you must be whiling she must be whiling we must be whiling you must be whiling they must be whiling
Perfect
I must have whiled you must have whiled she must have whiled we must have whiled you must have whiled they must have whiled
V-ing perfect
I must have been whiling you must have been whiling she must have been whiling we must have been whiling you must have been whiling they must have been whiling
Negation
Simple form
I must not while you must not while she must not while we must not while you must not while they must not while
V-ing form
I must not be whiling you must not be whiling she must not be whiling we must not be whiling you must not be whiling they must not be whiling
Perfect
I must not have whiled you must not have whiled she must not have whiled we must not have whiled you must not have whiled they must not have whiled
V-ing perfect
I must not have been whiling you must not have been whiling she must not have been whiling we must not have been whiling you must not have been whiling they must not have been whiling
Interrogative form
Simple form
must I while? must you while? must she while? must we while? must you while? must they while?
V-ing form
must I be whiling? must you be whiling? must she be whiling? must we be whiling? must you be whiling? must they be whiling?
Perfect
must I have whiled? must you have whiled? must she have whiled? must we have whiled? must you have whiled? must they have whiled?
V-ing perfect
must I have been whiling? must you have been whiling? must she have been whiling? must we have been whiling? must you have been whiling? must they have been whiling?
Interro-negative form
Simple form
must I not while? must you not while? must she not while? must we not while? must you not while? must they not while?
V-ing form
must I not be whiling? must you not be whiling? must she not be whiling? must we not be whiling? must you not be whiling? must they not be whiling?
Perfect
must I not have whiled? must you not have whiled? must she not have whiled? must we not have whiled? must you not have whiled? must they not have whiled?
V-ing perfect
must I not have been whiling? must you not have been whiling? must she not have been whiling? must we not have been whiling? must you not have been whiling? must they not have been whiling?