I must ache you must ache he must ache we must ache you must ache they must ache
V-ing form
I must be aching you must be aching he must be aching we must be aching you must be aching they must be aching
Perfect
I must have ached you must have ached he must have ached we must have ached you must have ached they must have ached
V-ing perfect
I must have been aching you must have been aching he must have been aching we must have been aching you must have been aching they must have been aching
Negation
Simple form
I mustn't ache you mustn't ache he mustn't ache we mustn't ache you mustn't ache they mustn't ache
V-ing form
I mustn't be aching you mustn't be aching he mustn't be aching we mustn't be aching you mustn't be aching they mustn't be aching
Perfect
I mustn't have ached you mustn't have ached he mustn't have ached we mustn't have ached you mustn't have ached they mustn't have ached
V-ing perfect
I mustn't have been aching you mustn't have been aching he mustn't have been aching we mustn't have been aching you mustn't have been aching they mustn't have been aching
Interrogative form
Simple form
must I ache? must you ache? must he ache? must we ache? must you ache? must they ache?
V-ing form
must I be aching? must you be aching? must he be aching? must we be aching? must you be aching? must they be aching?
Perfect
must I have ached? must you have ached? must he have ached? must we have ached? must you have ached? must they have ached?
V-ing perfect
must I have been aching? must you have been aching? must he have been aching? must we have been aching? must you have been aching? must they have been aching?
Interro-negative form
Simple form
mustn't I ache? mustn't you ache? mustn't he ache? mustn't we ache? mustn't you ache? mustn't they ache?
V-ing form
mustn't I be aching? mustn't you be aching? mustn't he be aching? mustn't we be aching? mustn't you be aching? mustn't they be aching?
Perfect
mustn't I have ached? mustn't you have ached? mustn't he have ached? mustn't we have ached? mustn't you have ached? mustn't they have ached?
V-ing perfect
mustn't I have been aching? mustn't you have been aching? mustn't he have been aching? mustn't we have been aching? mustn't you have been aching? mustn't they have been aching?