I must database you must database she must database we must database you must database they must database
V-ing form
I must be databasing you must be databasing she must be databasing we must be databasing you must be databasing they must be databasing
Perfect
I must have databased you must have databased she must have databased we must have databased you must have databased they must have databased
V-ing perfect
I must have been databasing you must have been databasing she must have been databasing we must have been databasing you must have been databasing they must have been databasing
Negation
Simple form
I must not database you must not database she must not database we must not database you must not database they must not database
V-ing form
I must not be databasing you must not be databasing she must not be databasing we must not be databasing you must not be databasing they must not be databasing
Perfect
I must not have databased you must not have databased she must not have databased we must not have databased you must not have databased they must not have databased
V-ing perfect
I must not have been databasing you must not have been databasing she must not have been databasing we must not have been databasing you must not have been databasing they must not have been databasing
Interrogative form
Simple form
must I database? must you database? must she database? must we database? must you database? must they database?
V-ing form
must I be databasing? must you be databasing? must she be databasing? must we be databasing? must you be databasing? must they be databasing?
Perfect
must I have databased? must you have databased? must she have databased? must we have databased? must you have databased? must they have databased?
V-ing perfect
must I have been databasing? must you have been databasing? must she have been databasing? must we have been databasing? must you have been databasing? must they have been databasing?
Interro-negative form
Simple form
must I not database? must you not database? must she not database? must we not database? must you not database? must they not database?
V-ing form
must I not be databasing? must you not be databasing? must she not be databasing? must we not be databasing? must you not be databasing? must they not be databasing?
Perfect
must I not have databased? must you not have databased? must she not have databased? must we not have databased? must you not have databased? must they not have databased?
V-ing perfect
must I not have been databasing? must you not have been databasing? must she not have been databasing? must we not have been databasing? must you not have been databasing? must they not have been databasing?