I must search you must search he must search we must search you must search they must search
V-ing form
I must be searching you must be searching he must be searching we must be searching you must be searching they must be searching
Perfect
I must have searched you must have searched he must have searched we must have searched you must have searched they must have searched
V-ing perfect
I must have been searching you must have been searching he must have been searching we must have been searching you must have been searching they must have been searching
Negation
Simple form
I must not search you must not search he must not search we must not search you must not search they must not search
V-ing form
I must not be searching you must not be searching he must not be searching we must not be searching you must not be searching they must not be searching
Perfect
I must not have searched you must not have searched he must not have searched we must not have searched you must not have searched they must not have searched
V-ing perfect
I must not have been searching you must not have been searching he must not have been searching we must not have been searching you must not have been searching they must not have been searching
Interrogative form
Simple form
must I search? must you search? must he search? must we search? must you search? must they search?
V-ing form
must I be searching? must you be searching? must he be searching? must we be searching? must you be searching? must they be searching?
Perfect
must I have searched? must you have searched? must he have searched? must we have searched? must you have searched? must they have searched?
V-ing perfect
must I have been searching? must you have been searching? must he have been searching? must we have been searching? must you have been searching? must they have been searching?
Interro-negative form
Simple form
must I not search? must you not search? must he not search? must we not search? must you not search? must they not search?
V-ing form
must I not be searching? must you not be searching? must he not be searching? must we not be searching? must you not be searching? must they not be searching?
Perfect
must I not have searched? must you not have searched? must he not have searched? must we not have searched? must you not have searched? must they not have searched?
V-ing perfect
must I not have been searching? must you not have been searching? must he not have been searching? must we not have been searching? must you not have been searching? must they not have been searching?