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