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