I must interface you must interface he must interface we must interface you must interface they must interface
V-ing form
I must be interfacing you must be interfacing he must be interfacing we must be interfacing you must be interfacing they must be interfacing
Perfect
I must have interfaced you must have interfaced he must have interfaced we must have interfaced you must have interfaced they must have interfaced
V-ing perfect
I must have been interfacing you must have been interfacing he must have been interfacing we must have been interfacing you must have been interfacing they must have been interfacing
Negation
Simple form
I must not interface you must not interface he must not interface we must not interface you must not interface they must not interface
V-ing form
I must not be interfacing you must not be interfacing he must not be interfacing we must not be interfacing you must not be interfacing they must not be interfacing
Perfect
I must not have interfaced you must not have interfaced he must not have interfaced we must not have interfaced you must not have interfaced they must not have interfaced
V-ing perfect
I must not have been interfacing you must not have been interfacing he must not have been interfacing we must not have been interfacing you must not have been interfacing they must not have been interfacing
Interrogative form
Simple form
must I interface? must you interface? must he interface? must we interface? must you interface? must they interface?
V-ing form
must I be interfacing? must you be interfacing? must he be interfacing? must we be interfacing? must you be interfacing? must they be interfacing?
Perfect
must I have interfaced? must you have interfaced? must he have interfaced? must we have interfaced? must you have interfaced? must they have interfaced?
V-ing perfect
must I have been interfacing? must you have been interfacing? must he have been interfacing? must we have been interfacing? must you have been interfacing? must they have been interfacing?
Interro-negative form
Simple form
must I not interface? must you not interface? must he not interface? must we not interface? must you not interface? must they not interface?
V-ing form
must I not be interfacing? must you not be interfacing? must he not be interfacing? must we not be interfacing? must you not be interfacing? must they not be interfacing?
Perfect
must I not have interfaced? must you not have interfaced? must he not have interfaced? must we not have interfaced? must you not have interfaced? must they not have interfaced?
V-ing perfect
must I not have been interfacing? must you not have been interfacing? must he not have been interfacing? must we not have been interfacing? must you not have been interfacing? must they not have been interfacing?