I must lament you must lament he must lament we must lament you must lament they must lament
V-ing form
I must be lamenting you must be lamenting he must be lamenting we must be lamenting you must be lamenting they must be lamenting
Perfect
I must have lamented you must have lamented he must have lamented we must have lamented you must have lamented they must have lamented
V-ing perfect
I must have been lamenting you must have been lamenting he must have been lamenting we must have been lamenting you must have been lamenting they must have been lamenting
Negation
Simple form
I must not lament you must not lament he must not lament we must not lament you must not lament they must not lament
V-ing form
I must not be lamenting you must not be lamenting he must not be lamenting we must not be lamenting you must not be lamenting they must not be lamenting
Perfect
I must not have lamented you must not have lamented he must not have lamented we must not have lamented you must not have lamented they must not have lamented
V-ing perfect
I must not have been lamenting you must not have been lamenting he must not have been lamenting we must not have been lamenting you must not have been lamenting they must not have been lamenting
Interrogative form
Simple form
must I lament? must you lament? must he lament? must we lament? must you lament? must they lament?
V-ing form
must I be lamenting? must you be lamenting? must he be lamenting? must we be lamenting? must you be lamenting? must they be lamenting?
Perfect
must I have lamented? must you have lamented? must he have lamented? must we have lamented? must you have lamented? must they have lamented?
V-ing perfect
must I have been lamenting? must you have been lamenting? must he have been lamenting? must we have been lamenting? must you have been lamenting? must they have been lamenting?
Interro-negative form
Simple form
must I not lament? must you not lament? must he not lament? must we not lament? must you not lament? must they not lament?
V-ing form
must I not be lamenting? must you not be lamenting? must he not be lamenting? must we not be lamenting? must you not be lamenting? must they not be lamenting?
Perfect
must I not have lamented? must you not have lamented? must he not have lamented? must we not have lamented? must you not have lamented? must they not have lamented?
V-ing perfect
must I not have been lamenting? must you not have been lamenting? must he not have been lamenting? must we not have been lamenting? must you not have been lamenting? must they not have been lamenting?