I must deteriorate you must deteriorate he must deteriorate we must deteriorate you must deteriorate they must deteriorate
V-ing form
I must be deteriorating you must be deteriorating he must be deteriorating we must be deteriorating you must be deteriorating they must be deteriorating
Perfect
I must have deteriorated you must have deteriorated he must have deteriorated we must have deteriorated you must have deteriorated they must have deteriorated
V-ing perfect
I must have been deteriorating you must have been deteriorating he must have been deteriorating we must have been deteriorating you must have been deteriorating they must have been deteriorating
Negation
Simple form
I must not deteriorate you must not deteriorate he must not deteriorate we must not deteriorate you must not deteriorate they must not deteriorate
V-ing form
I must not be deteriorating you must not be deteriorating he must not be deteriorating we must not be deteriorating you must not be deteriorating they must not be deteriorating
Perfect
I must not have deteriorated you must not have deteriorated he must not have deteriorated we must not have deteriorated you must not have deteriorated they must not have deteriorated
V-ing perfect
I must not have been deteriorating you must not have been deteriorating he must not have been deteriorating we must not have been deteriorating you must not have been deteriorating they must not have been deteriorating
Interrogative form
Simple form
must I deteriorate? must you deteriorate? must he deteriorate? must we deteriorate? must you deteriorate? must they deteriorate?
V-ing form
must I be deteriorating? must you be deteriorating? must he be deteriorating? must we be deteriorating? must you be deteriorating? must they be deteriorating?
Perfect
must I have deteriorated? must you have deteriorated? must he have deteriorated? must we have deteriorated? must you have deteriorated? must they have deteriorated?
V-ing perfect
must I have been deteriorating? must you have been deteriorating? must he have been deteriorating? must we have been deteriorating? must you have been deteriorating? must they have been deteriorating?
Interro-negative form
Simple form
must I not deteriorate? must you not deteriorate? must he not deteriorate? must we not deteriorate? must you not deteriorate? must they not deteriorate?
V-ing form
must I not be deteriorating? must you not be deteriorating? must he not be deteriorating? must we not be deteriorating? must you not be deteriorating? must they not be deteriorating?
Perfect
must I not have deteriorated? must you not have deteriorated? must he not have deteriorated? must we not have deteriorated? must you not have deteriorated? must they not have deteriorated?
V-ing perfect
must I not have been deteriorating? must you not have been deteriorating? must he not have been deteriorating? must we not have been deteriorating? must you not have been deteriorating? must they not have been deteriorating?