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