I must secrete you must secrete he must secrete we must secrete you must secrete they must secrete
V-ing form
I must be secreting you must be secreting he must be secreting we must be secreting you must be secreting they must be secreting
Perfect
I must have secreted you must have secreted he must have secreted we must have secreted you must have secreted they must have secreted
V-ing perfect
I must have been secreting you must have been secreting he must have been secreting we must have been secreting you must have been secreting they must have been secreting
Negation
Simple form
I must not secrete you must not secrete he must not secrete we must not secrete you must not secrete they must not secrete
V-ing form
I must not be secreting you must not be secreting he must not be secreting we must not be secreting you must not be secreting they must not be secreting
Perfect
I must not have secreted you must not have secreted he must not have secreted we must not have secreted you must not have secreted they must not have secreted
V-ing perfect
I must not have been secreting you must not have been secreting he must not have been secreting we must not have been secreting you must not have been secreting they must not have been secreting
Interrogative form
Simple form
must I secrete? must you secrete? must he secrete? must we secrete? must you secrete? must they secrete?
V-ing form
must I be secreting? must you be secreting? must he be secreting? must we be secreting? must you be secreting? must they be secreting?
Perfect
must I have secreted? must you have secreted? must he have secreted? must we have secreted? must you have secreted? must they have secreted?
V-ing perfect
must I have been secreting? must you have been secreting? must he have been secreting? must we have been secreting? must you have been secreting? must they have been secreting?
Interro-negative form
Simple form
must I not secrete? must you not secrete? must he not secrete? must we not secrete? must you not secrete? must they not secrete?
V-ing form
must I not be secreting? must you not be secreting? must he not be secreting? must we not be secreting? must you not be secreting? must they not be secreting?
Perfect
must I not have secreted? must you not have secreted? must he not have secreted? must we not have secreted? must you not have secreted? must they not have secreted?
V-ing perfect
must I not have been secreting? must you not have been secreting? must he not have been secreting? must we not have been secreting? must you not have been secreting? must they not have been secreting?