I must skin-dive you must skin-dive he must skin-dive we must skin-dive you must skin-dive they must skin-dive
V-ing form
I must be skin-diving you must be skin-diving he must be skin-diving we must be skin-diving you must be skin-diving they must be skin-diving
Perfect
I must have skin-dived you must have skin-dived he must have skin-dived we must have skin-dived you must have skin-dived they must have skin-dived
V-ing perfect
I must have been skin-diving you must have been skin-diving he must have been skin-diving we must have been skin-diving you must have been skin-diving they must have been skin-diving
Negation
Simple form
I must not skin-dive you must not skin-dive he must not skin-dive we must not skin-dive you must not skin-dive they must not skin-dive
V-ing form
I must not be skin-diving you must not be skin-diving he must not be skin-diving we must not be skin-diving you must not be skin-diving they must not be skin-diving
Perfect
I must not have skin-dived you must not have skin-dived he must not have skin-dived we must not have skin-dived you must not have skin-dived they must not have skin-dived
V-ing perfect
I must not have been skin-diving you must not have been skin-diving he must not have been skin-diving we must not have been skin-diving you must not have been skin-diving they must not have been skin-diving
Interrogative form
Simple form
must I skin-dive? must you skin-dive? must he skin-dive? must we skin-dive? must you skin-dive? must they skin-dive?
V-ing form
must I be skin-diving? must you be skin-diving? must he be skin-diving? must we be skin-diving? must you be skin-diving? must they be skin-diving?
Perfect
must I have skin-dived? must you have skin-dived? must he have skin-dived? must we have skin-dived? must you have skin-dived? must they have skin-dived?
V-ing perfect
must I have been skin-diving? must you have been skin-diving? must he have been skin-diving? must we have been skin-diving? must you have been skin-diving? must they have been skin-diving?
Interro-negative form
Simple form
must I not skin-dive? must you not skin-dive? must he not skin-dive? must we not skin-dive? must you not skin-dive? must they not skin-dive?
V-ing form
must I not be skin-diving? must you not be skin-diving? must he not be skin-diving? must we not be skin-diving? must you not be skin-diving? must they not be skin-diving?
Perfect
must I not have skin-dived? must you not have skin-dived? must he not have skin-dived? must we not have skin-dived? must you not have skin-dived? must they not have skin-dived?
V-ing perfect
must I not have been skin-diving? must you not have been skin-diving? must he not have been skin-diving? must we not have been skin-diving? must you not have been skin-diving? must they not have been skin-diving?