I must lave you must lave he must lave we must lave you must lave they must lave
V-ing form
I must be laving you must be laving he must be laving we must be laving you must be laving they must be laving
Perfect
I must have laved you must have laved he must have laved we must have laved you must have laved they must have laved
V-ing perfect
I must have been laving you must have been laving he must have been laving we must have been laving you must have been laving they must have been laving
Negation
Simple form
I must not lave you must not lave he must not lave we must not lave you must not lave they must not lave
V-ing form
I must not be laving you must not be laving he must not be laving we must not be laving you must not be laving they must not be laving
Perfect
I must not have laved you must not have laved he must not have laved we must not have laved you must not have laved they must not have laved
V-ing perfect
I must not have been laving you must not have been laving he must not have been laving we must not have been laving you must not have been laving they must not have been laving
Interrogative form
Simple form
must I lave? must you lave? must he lave? must we lave? must you lave? must they lave?
V-ing form
must I be laving? must you be laving? must he be laving? must we be laving? must you be laving? must they be laving?
Perfect
must I have laved? must you have laved? must he have laved? must we have laved? must you have laved? must they have laved?
V-ing perfect
must I have been laving? must you have been laving? must he have been laving? must we have been laving? must you have been laving? must they have been laving?
Interro-negative form
Simple form
must I not lave? must you not lave? must he not lave? must we not lave? must you not lave? must they not lave?
V-ing form
must I not be laving? must you not be laving? must he not be laving? must we not be laving? must you not be laving? must they not be laving?
Perfect
must I not have laved? must you not have laved? must he not have laved? must we not have laved? must you not have laved? must they not have laved?
V-ing perfect
must I not have been laving? must you not have been laving? must he not have been laving? must we not have been laving? must you not have been laving? must they not have been laving?