I must spur you must spur she must spur we must spur you must spur they must spur
V-ing form
I must be spurring you must be spurring she must be spurring we must be spurring you must be spurring they must be spurring
Perfect
I must have spurred you must have spurred she 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 she must have been spurring we must have been spurring you must have been spurring they must have been spurring
Negation
Simple form
I must not spur you must not spur she must not spur we must not spur you must not spur they must not spur
V-ing form
I must not be spurring you must not be spurring she must not be spurring we must not be spurring you must not be spurring they must not be spurring
Perfect
I must not have spurred you must not have spurred she must not have spurred we must not have spurred you must not have spurred they must not have spurred
V-ing perfect
I must not have been spurring you must not have been spurring she must not have been spurring we must not have been spurring you must not have been spurring they must not have been spurring
Interrogative form
Simple form
must I spur? must you spur? must she spur? must we spur? must you spur? must they spur?
V-ing form
must I be spurring? must you be spurring? must she be spurring? must we be spurring? must you be spurring? must they be spurring?
Perfect
must I have spurred? must you have spurred? must she 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 she have been spurring? must we have been spurring? must you have been spurring? must they have been spurring?
Interro-negative form
Simple form
must I not spur? must you not spur? must she not spur? must we not spur? must you not spur? must they not spur?
V-ing form
must I not be spurring? must you not be spurring? must she not be spurring? must we not be spurring? must you not be spurring? must they not be spurring?
Perfect
must I not have spurred? must you not have spurred? must she not have spurred? must we not have spurred? must you not have spurred? must they not have spurred?
V-ing perfect
must I not have been spurring? must you not have been spurring? must she not have been spurring? must we not have been spurring? must you not have been spurring? must they not have been spurring?