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