I must snake you must snake she must snake we must snake you must snake they must snake
V-ing form
I must be snaking you must be snaking she must be snaking we must be snaking you must be snaking they must be snaking
Perfect
I must have snaked you must have snaked she must have snaked we must have snaked you must have snaked they must have snaked
V-ing perfect
I must have been snaking you must have been snaking she must have been snaking we must have been snaking you must have been snaking they must have been snaking
Negation
Simple form
I must not snake you must not snake she must not snake we must not snake you must not snake they must not snake
V-ing form
I must not be snaking you must not be snaking she must not be snaking we must not be snaking you must not be snaking they must not be snaking
Perfect
I must not have snaked you must not have snaked she must not have snaked we must not have snaked you must not have snaked they must not have snaked
V-ing perfect
I must not have been snaking you must not have been snaking she must not have been snaking we must not have been snaking you must not have been snaking they must not have been snaking
Interrogative form
Simple form
must I snake? must you snake? must she snake? must we snake? must you snake? must they snake?
V-ing form
must I be snaking? must you be snaking? must she be snaking? must we be snaking? must you be snaking? must they be snaking?
Perfect
must I have snaked? must you have snaked? must she have snaked? must we have snaked? must you have snaked? must they have snaked?
V-ing perfect
must I have been snaking? must you have been snaking? must she have been snaking? must we have been snaking? must you have been snaking? must they have been snaking?
Interro-negative form
Simple form
must I not snake? must you not snake? must she not snake? must we not snake? must you not snake? must they not snake?
V-ing form
must I not be snaking? must you not be snaking? must she not be snaking? must we not be snaking? must you not be snaking? must they not be snaking?
Perfect
must I not have snaked? must you not have snaked? must she not have snaked? must we not have snaked? must you not have snaked? must they not have snaked?
V-ing perfect
must I not have been snaking? must you not have been snaking? must she not have been snaking? must we not have been snaking? must you not have been snaking? must they not have been snaking?