I must operate you must operate he must operate we must operate you must operate they must operate
V-ing form
I must be operating you must be operating he must be operating we must be operating you must be operating they must be operating
Perfect
I must have operated you must have operated he must have operated we must have operated you must have operated they must have operated
V-ing perfect
I must have been operating you must have been operating he must have been operating we must have been operating you must have been operating they must have been operating
Negation
Simple form
I must not operate you must not operate he must not operate we must not operate you must not operate they must not operate
V-ing form
I must not be operating you must not be operating he must not be operating we must not be operating you must not be operating they must not be operating
Perfect
I must not have operated you must not have operated he must not have operated we must not have operated you must not have operated they must not have operated
V-ing perfect
I must not have been operating you must not have been operating he must not have been operating we must not have been operating you must not have been operating they must not have been operating
Interrogative form
Simple form
must I operate? must you operate? must he operate? must we operate? must you operate? must they operate?
V-ing form
must I be operating? must you be operating? must he be operating? must we be operating? must you be operating? must they be operating?
Perfect
must I have operated? must you have operated? must he have operated? must we have operated? must you have operated? must they have operated?
V-ing perfect
must I have been operating? must you have been operating? must he have been operating? must we have been operating? must you have been operating? must they have been operating?
Interro-negative form
Simple form
must I not operate? must you not operate? must he not operate? must we not operate? must you not operate? must they not operate?
V-ing form
must I not be operating? must you not be operating? must he not be operating? must we not be operating? must you not be operating? must they not be operating?
Perfect
must I not have operated? must you not have operated? must he not have operated? must we not have operated? must you not have operated? must they not have operated?
V-ing perfect
must I not have been operating? must you not have been operating? must he not have been operating? must we not have been operating? must you not have been operating? must they not have been operating?