I must invent you must invent he must invent we must invent you must invent they must invent
V-ing form
I must be inventing you must be inventing he must be inventing we must be inventing you must be inventing they must be inventing
Perfect
I must have invented you must have invented he 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 he 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 he 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 he 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 he 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 he 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 he invent? must we invent? must you invent? must they invent?
V-ing form
must I be inventing? must you be inventing? must he be inventing? must we be inventing? must you be inventing? must they be inventing?
Perfect
must I have invented? must you have invented? must he 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 he 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 he 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 he 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 he 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 he not have been inventing? must we not have been inventing? must you not have been inventing? must they not have been inventing?