I must surface you must surface he must surface we must surface you must surface they must surface
V-ing form
I must be surfacing you must be surfacing he must be surfacing we must be surfacing you must be surfacing they must be surfacing
Perfect
I must have surfaced you must have surfaced he must have surfaced we must have surfaced you must have surfaced they must have surfaced
V-ing perfect
I must have been surfacing you must have been surfacing he must have been surfacing we must have been surfacing you must have been surfacing they must have been surfacing
Negation
Simple form
I must not surface you must not surface he must not surface we must not surface you must not surface they must not surface
V-ing form
I must not be surfacing you must not be surfacing he must not be surfacing we must not be surfacing you must not be surfacing they must not be surfacing
Perfect
I must not have surfaced you must not have surfaced he must not have surfaced we must not have surfaced you must not have surfaced they must not have surfaced
V-ing perfect
I must not have been surfacing you must not have been surfacing he must not have been surfacing we must not have been surfacing you must not have been surfacing they must not have been surfacing
Interrogative form
Simple form
must I surface? must you surface? must he surface? must we surface? must you surface? must they surface?
V-ing form
must I be surfacing? must you be surfacing? must he be surfacing? must we be surfacing? must you be surfacing? must they be surfacing?
Perfect
must I have surfaced? must you have surfaced? must he have surfaced? must we have surfaced? must you have surfaced? must they have surfaced?
V-ing perfect
must I have been surfacing? must you have been surfacing? must he have been surfacing? must we have been surfacing? must you have been surfacing? must they have been surfacing?
Interro-negative form
Simple form
must I not surface? must you not surface? must he not surface? must we not surface? must you not surface? must they not surface?
V-ing form
must I not be surfacing? must you not be surfacing? must he not be surfacing? must we not be surfacing? must you not be surfacing? must they not be surfacing?
Perfect
must I not have surfaced? must you not have surfaced? must he not have surfaced? must we not have surfaced? must you not have surfaced? must they not have surfaced?
V-ing perfect
must I not have been surfacing? must you not have been surfacing? must he not have been surfacing? must we not have been surfacing? must you not have been surfacing? must they not have been surfacing?