I must follow you must follow she must follow we must follow you must follow they must follow
V-ing form
I must be following you must be following she must be following we must be following you must be following they must be following
Perfect
I must have followed you must have followed she must have followed we must have followed you must have followed they must have followed
V-ing perfect
I must have been following you must have been following she must have been following we must have been following you must have been following they must have been following
Negation
Simple form
I mustn't follow you mustn't follow she mustn't follow we mustn't follow you mustn't follow they mustn't follow
V-ing form
I mustn't be following you mustn't be following she mustn't be following we mustn't be following you mustn't be following they mustn't be following
Perfect
I mustn't have followed you mustn't have followed she mustn't have followed we mustn't have followed you mustn't have followed they mustn't have followed
V-ing perfect
I mustn't have been following you mustn't have been following she mustn't have been following we mustn't have been following you mustn't have been following they mustn't have been following
Interrogative form
Simple form
must I follow? must you follow? must she follow? must we follow? must you follow? must they follow?
V-ing form
must I be following? must you be following? must she be following? must we be following? must you be following? must they be following?
Perfect
must I have followed? must you have followed? must she have followed? must we have followed? must you have followed? must they have followed?
V-ing perfect
must I have been following? must you have been following? must she have been following? must we have been following? must you have been following? must they have been following?
Interro-negative form
Simple form
mustn't I follow? mustn't you follow? mustn't she follow? mustn't we follow? mustn't you follow? mustn't they follow?
V-ing form
mustn't I be following? mustn't you be following? mustn't she be following? mustn't we be following? mustn't you be following? mustn't they be following?
Perfect
mustn't I have followed? mustn't you have followed? mustn't she have followed? mustn't we have followed? mustn't you have followed? mustn't they have followed?
V-ing perfect
mustn't I have been following? mustn't you have been following? mustn't she have been following? mustn't we have been following? mustn't you have been following? mustn't they have been following?