I must reef you must reef he must reef we must reef you must reef they must reef
V-ing form
I must be reefing you must be reefing he must be reefing we must be reefing you must be reefing they must be reefing
Perfect
I must have reefed you must have reefed he must have reefed we must have reefed you must have reefed they must have reefed
V-ing perfect
I must have been reefing you must have been reefing he must have been reefing we must have been reefing you must have been reefing they must have been reefing
Negation
Simple form
I mustn't reef you mustn't reef he mustn't reef we mustn't reef you mustn't reef they mustn't reef
V-ing form
I mustn't be reefing you mustn't be reefing he mustn't be reefing we mustn't be reefing you mustn't be reefing they mustn't be reefing
Perfect
I mustn't have reefed you mustn't have reefed he mustn't have reefed we mustn't have reefed you mustn't have reefed they mustn't have reefed
V-ing perfect
I mustn't have been reefing you mustn't have been reefing he mustn't have been reefing we mustn't have been reefing you mustn't have been reefing they mustn't have been reefing
Interrogative form
Simple form
must I reef? must you reef? must he reef? must we reef? must you reef? must they reef?
V-ing form
must I be reefing? must you be reefing? must he be reefing? must we be reefing? must you be reefing? must they be reefing?
Perfect
must I have reefed? must you have reefed? must he have reefed? must we have reefed? must you have reefed? must they have reefed?
V-ing perfect
must I have been reefing? must you have been reefing? must he have been reefing? must we have been reefing? must you have been reefing? must they have been reefing?
Interro-negative form
Simple form
mustn't I reef? mustn't you reef? mustn't he reef? mustn't we reef? mustn't you reef? mustn't they reef?
V-ing form
mustn't I be reefing? mustn't you be reefing? mustn't he be reefing? mustn't we be reefing? mustn't you be reefing? mustn't they be reefing?
Perfect
mustn't I have reefed? mustn't you have reefed? mustn't he have reefed? mustn't we have reefed? mustn't you have reefed? mustn't they have reefed?
V-ing perfect
mustn't I have been reefing? mustn't you have been reefing? mustn't he have been reefing? mustn't we have been reefing? mustn't you have been reefing? mustn't they have been reefing?