I must threaten you must threaten he must threaten we must threaten you must threaten they must threaten
V-ing form
I must be threatening you must be threatening he must be threatening we must be threatening you must be threatening they must be threatening
Perfect
I must have threatened you must have threatened he must have threatened we must have threatened you must have threatened they must have threatened
V-ing perfect
I must have been threatening you must have been threatening he must have been threatening we must have been threatening you must have been threatening they must have been threatening
Negation
Simple form
I must not threaten you must not threaten he must not threaten we must not threaten you must not threaten they must not threaten
V-ing form
I must not be threatening you must not be threatening he must not be threatening we must not be threatening you must not be threatening they must not be threatening
Perfect
I must not have threatened you must not have threatened he must not have threatened we must not have threatened you must not have threatened they must not have threatened
V-ing perfect
I must not have been threatening you must not have been threatening he must not have been threatening we must not have been threatening you must not have been threatening they must not have been threatening
Interrogative form
Simple form
must I threaten? must you threaten? must he threaten? must we threaten? must you threaten? must they threaten?
V-ing form
must I be threatening? must you be threatening? must he be threatening? must we be threatening? must you be threatening? must they be threatening?
Perfect
must I have threatened? must you have threatened? must he have threatened? must we have threatened? must you have threatened? must they have threatened?
V-ing perfect
must I have been threatening? must you have been threatening? must he have been threatening? must we have been threatening? must you have been threatening? must they have been threatening?
Interro-negative form
Simple form
must I not threaten? must you not threaten? must he not threaten? must we not threaten? must you not threaten? must they not threaten?
V-ing form
must I not be threatening? must you not be threatening? must he not be threatening? must we not be threatening? must you not be threatening? must they not be threatening?
Perfect
must I not have threatened? must you not have threatened? must he not have threatened? must we not have threatened? must you not have threatened? must they not have threatened?
V-ing perfect
must I not have been threatening? must you not have been threatening? must he not have been threatening? must we not have been threatening? must you not have been threatening? must they not have been threatening?