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