I must fetch you must fetch she must fetch we must fetch you must fetch they must fetch
V-ing form
I must be fetching you must be fetching she must be fetching we must be fetching you must be fetching they must be fetching
Perfect
I must have fetched you must have fetched she must have fetched we must have fetched you must have fetched they must have fetched
V-ing perfect
I must have been fetching you must have been fetching she must have been fetching we must have been fetching you must have been fetching they must have been fetching
Negation
Simple form
I mustn't fetch you mustn't fetch she mustn't fetch we mustn't fetch you mustn't fetch they mustn't fetch
V-ing form
I mustn't be fetching you mustn't be fetching she mustn't be fetching we mustn't be fetching you mustn't be fetching they mustn't be fetching
Perfect
I mustn't have fetched you mustn't have fetched she mustn't have fetched we mustn't have fetched you mustn't have fetched they mustn't have fetched
V-ing perfect
I mustn't have been fetching you mustn't have been fetching she mustn't have been fetching we mustn't have been fetching you mustn't have been fetching they mustn't have been fetching
Interrogative form
Simple form
must I fetch? must you fetch? must she fetch? must we fetch? must you fetch? must they fetch?
V-ing form
must I be fetching? must you be fetching? must she be fetching? must we be fetching? must you be fetching? must they be fetching?
Perfect
must I have fetched? must you have fetched? must she have fetched? must we have fetched? must you have fetched? must they have fetched?
V-ing perfect
must I have been fetching? must you have been fetching? must she have been fetching? must we have been fetching? must you have been fetching? must they have been fetching?
Interro-negative form
Simple form
mustn't I fetch? mustn't you fetch? mustn't she fetch? mustn't we fetch? mustn't you fetch? mustn't they fetch?
V-ing form
mustn't I be fetching? mustn't you be fetching? mustn't she be fetching? mustn't we be fetching? mustn't you be fetching? mustn't they be fetching?
Perfect
mustn't I have fetched? mustn't you have fetched? mustn't she have fetched? mustn't we have fetched? mustn't you have fetched? mustn't they have fetched?
V-ing perfect
mustn't I have been fetching? mustn't you have been fetching? mustn't she have been fetching? mustn't we have been fetching? mustn't you have been fetching? mustn't they have been fetching?