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 mustn't snake you mustn't snake she mustn't snake we mustn't snake you mustn't snake they mustn't snake
V-ing form
I mustn't be snaking you mustn't be snaking she mustn't be snaking we mustn't be snaking you mustn't be snaking they mustn't be snaking
Perfect
I mustn't have snaked you mustn't have snaked she mustn't have snaked we mustn't have snaked you mustn't have snaked they mustn't have snaked
V-ing perfect
I mustn't have been snaking you mustn't have been snaking she mustn't have been snaking we mustn't have been snaking you mustn't have been snaking they mustn't 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
mustn't I snake? mustn't you snake? mustn't she snake? mustn't we snake? mustn't you snake? mustn't they snake?
V-ing form
mustn't I be snaking? mustn't you be snaking? mustn't she be snaking? mustn't we be snaking? mustn't you be snaking? mustn't they be snaking?
Perfect
mustn't I have snaked? mustn't you have snaked? mustn't she have snaked? mustn't we have snaked? mustn't you have snaked? mustn't they have snaked?
V-ing perfect
mustn't I have been snaking? mustn't you have been snaking? mustn't she have been snaking? mustn't we have been snaking? mustn't you have been snaking? mustn't they have been snaking?