I must sneak you must sneak she must sneak we must sneak you must sneak they must sneak
V-ing form
I must be sneaking you must be sneaking she must be sneaking we must be sneaking you must be sneaking they must be sneaking
Perfect
I must have snuck you must have snuck she must have snuck we must have snuck you must have snuck they must have snuck
V-ing perfect
I must have been sneaking you must have been sneaking she must have been sneaking we must have been sneaking you must have been sneaking they must have been sneaking
Negation
Simple form
I must not sneak you must not sneak she must not sneak we must not sneak you must not sneak they must not sneak
V-ing form
I must not be sneaking you must not be sneaking she must not be sneaking we must not be sneaking you must not be sneaking they must not be sneaking
Perfect
I must not have snuck you must not have snuck she must not have snuck we must not have snuck you must not have snuck they must not have snuck
V-ing perfect
I must not have been sneaking you must not have been sneaking she must not have been sneaking we must not have been sneaking you must not have been sneaking they must not have been sneaking
Interrogative form
Simple form
must I sneak? must you sneak? must she sneak? must we sneak? must you sneak? must they sneak?
V-ing form
must I be sneaking? must you be sneaking? must she be sneaking? must we be sneaking? must you be sneaking? must they be sneaking?
Perfect
must I have snuck? must you have snuck? must she have snuck? must we have snuck? must you have snuck? must they have snuck?
V-ing perfect
must I have been sneaking? must you have been sneaking? must she have been sneaking? must we have been sneaking? must you have been sneaking? must they have been sneaking?
Interro-negative form
Simple form
must I not sneak? must you not sneak? must she not sneak? must we not sneak? must you not sneak? must they not sneak?
V-ing form
must I not be sneaking? must you not be sneaking? must she not be sneaking? must we not be sneaking? must you not be sneaking? must they not be sneaking?
Perfect
must I not have snuck? must you not have snuck? must she not have snuck? must we not have snuck? must you not have snuck? must they not have snuck?
V-ing perfect
must I not have been sneaking? must you not have been sneaking? must she not have been sneaking? must we not have been sneaking? must you not have been sneaking? must they not have been sneaking?