I must invent you must invent she must invent we must invent you must invent they must invent
V-ing form
I must be inventing you must be inventing she must be inventing we must be inventing you must be inventing they must be inventing
Perfect
I must have invented you must have invented she must have invented we must have invented you must have invented they must have invented
V-ing perfect
I must have been inventing you must have been inventing she must have been inventing we must have been inventing you must have been inventing they must have been inventing
Negation
Simple form
I must not invent you must not invent she must not invent we must not invent you must not invent they must not invent
V-ing form
I must not be inventing you must not be inventing she must not be inventing we must not be inventing you must not be inventing they must not be inventing
Perfect
I must not have invented you must not have invented she must not have invented we must not have invented you must not have invented they must not have invented
V-ing perfect
I must not have been inventing you must not have been inventing she must not have been inventing we must not have been inventing you must not have been inventing they must not have been inventing
Interrogative form
Simple form
must I invent? must you invent? must she invent? must we invent? must you invent? must they invent?
V-ing form
must I be inventing? must you be inventing? must she be inventing? must we be inventing? must you be inventing? must they be inventing?
Perfect
must I have invented? must you have invented? must she have invented? must we have invented? must you have invented? must they have invented?
V-ing perfect
must I have been inventing? must you have been inventing? must she have been inventing? must we have been inventing? must you have been inventing? must they have been inventing?
Interro-negative form
Simple form
must I not invent? must you not invent? must she not invent? must we not invent? must you not invent? must they not invent?
V-ing form
must I not be inventing? must you not be inventing? must she not be inventing? must we not be inventing? must you not be inventing? must they not be inventing?
Perfect
must I not have invented? must you not have invented? must she not have invented? must we not have invented? must you not have invented? must they not have invented?
V-ing perfect
must I not have been inventing? must you not have been inventing? must she not have been inventing? must we not have been inventing? must you not have been inventing? must they not have been inventing?