I must winnow you must winnow he must winnow we must winnow you must winnow they must winnow
V-ing form
I must be winnowing you must be winnowing he must be winnowing we must be winnowing you must be winnowing they must be winnowing
Perfect
I must have winnowed you must have winnowed he must have winnowed we must have winnowed you must have winnowed they must have winnowed
V-ing perfect
I must have been winnowing you must have been winnowing he must have been winnowing we must have been winnowing you must have been winnowing they must have been winnowing
Negation
Simple form
I must not winnow you must not winnow he must not winnow we must not winnow you must not winnow they must not winnow
V-ing form
I must not be winnowing you must not be winnowing he must not be winnowing we must not be winnowing you must not be winnowing they must not be winnowing
Perfect
I must not have winnowed you must not have winnowed he must not have winnowed we must not have winnowed you must not have winnowed they must not have winnowed
V-ing perfect
I must not have been winnowing you must not have been winnowing he must not have been winnowing we must not have been winnowing you must not have been winnowing they must not have been winnowing
Interrogative form
Simple form
must I winnow? must you winnow? must he winnow? must we winnow? must you winnow? must they winnow?
V-ing form
must I be winnowing? must you be winnowing? must he be winnowing? must we be winnowing? must you be winnowing? must they be winnowing?
Perfect
must I have winnowed? must you have winnowed? must he have winnowed? must we have winnowed? must you have winnowed? must they have winnowed?
V-ing perfect
must I have been winnowing? must you have been winnowing? must he have been winnowing? must we have been winnowing? must you have been winnowing? must they have been winnowing?
Interro-negative form
Simple form
must I not winnow? must you not winnow? must he not winnow? must we not winnow? must you not winnow? must they not winnow?
V-ing form
must I not be winnowing? must you not be winnowing? must he not be winnowing? must we not be winnowing? must you not be winnowing? must they not be winnowing?
Perfect
must I not have winnowed? must you not have winnowed? must he not have winnowed? must we not have winnowed? must you not have winnowed? must they not have winnowed?
V-ing perfect
must I not have been winnowing? must you not have been winnowing? must he not have been winnowing? must we not have been winnowing? must you not have been winnowing? must they not have been winnowing?