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 must not surround you must not surround he must not surround we must not surround you must not surround they must not surround
V-ing form
I must not be surrounding you must not be surrounding he must not be surrounding we must not be surrounding you must not be surrounding they must not be surrounding
Perfect
I must not have surrounded you must not have surrounded he must not have surrounded we must not have surrounded you must not have surrounded they must not have surrounded
V-ing perfect
I must not have been surrounding you must not have been surrounding he must not have been surrounding we must not have been surrounding you must not have been surrounding they must not 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
must I not surround? must you not surround? must he not surround? must we not surround? must you not surround? must they not surround?
V-ing form
must I not be surrounding? must you not be surrounding? must he not be surrounding? must we not be surrounding? must you not be surrounding? must they not be surrounding?
Perfect
must I not have surrounded? must you not have surrounded? must he not have surrounded? must we not have surrounded? must you not have surrounded? must they not have surrounded?
V-ing perfect
must I not have been surrounding? must you not have been surrounding? must he not have been surrounding? must we not have been surrounding? must you not have been surrounding? must they not have been surrounding?