I must regard you must regard he must regard we must regard you must regard they must regard
V-ing form
I must be regarding you must be regarding he must be regarding we must be regarding you must be regarding they must be regarding
Perfect
I must have regarded you must have regarded he must have regarded we must have regarded you must have regarded they must have regarded
V-ing perfect
I must have been regarding you must have been regarding he must have been regarding we must have been regarding you must have been regarding they must have been regarding
Negation
Simple form
I must not regard you must not regard he must not regard we must not regard you must not regard they must not regard
V-ing form
I must not be regarding you must not be regarding he must not be regarding we must not be regarding you must not be regarding they must not be regarding
Perfect
I must not have regarded you must not have regarded he must not have regarded we must not have regarded you must not have regarded they must not have regarded
V-ing perfect
I must not have been regarding you must not have been regarding he must not have been regarding we must not have been regarding you must not have been regarding they must not have been regarding
Interrogative form
Simple form
must I regard? must you regard? must he regard? must we regard? must you regard? must they regard?
V-ing form
must I be regarding? must you be regarding? must he be regarding? must we be regarding? must you be regarding? must they be regarding?
Perfect
must I have regarded? must you have regarded? must he have regarded? must we have regarded? must you have regarded? must they have regarded?
V-ing perfect
must I have been regarding? must you have been regarding? must he have been regarding? must we have been regarding? must you have been regarding? must they have been regarding?
Interro-negative form
Simple form
must I not regard? must you not regard? must he not regard? must we not regard? must you not regard? must they not regard?
V-ing form
must I not be regarding? must you not be regarding? must he not be regarding? must we not be regarding? must you not be regarding? must they not be regarding?
Perfect
must I not have regarded? must you not have regarded? must he not have regarded? must we not have regarded? must you not have regarded? must they not have regarded?
V-ing perfect
must I not have been regarding? must you not have been regarding? must he not have been regarding? must we not have been regarding? must you not have been regarding? must they not have been regarding?