I must react you must react she must react we must react you must react they must react
V-ing form
I must be reacting you must be reacting she must be reacting we must be reacting you must be reacting they must be reacting
Perfect
I must have reacted you must have reacted she must have reacted we must have reacted you must have reacted they must have reacted
V-ing perfect
I must have been reacting you must have been reacting she must have been reacting we must have been reacting you must have been reacting they must have been reacting
Negation
Simple form
I must not react you must not react she must not react we must not react you must not react they must not react
V-ing form
I must not be reacting you must not be reacting she must not be reacting we must not be reacting you must not be reacting they must not be reacting
Perfect
I must not have reacted you must not have reacted she must not have reacted we must not have reacted you must not have reacted they must not have reacted
V-ing perfect
I must not have been reacting you must not have been reacting she must not have been reacting we must not have been reacting you must not have been reacting they must not have been reacting
Interrogative form
Simple form
must I react? must you react? must she react? must we react? must you react? must they react?
V-ing form
must I be reacting? must you be reacting? must she be reacting? must we be reacting? must you be reacting? must they be reacting?
Perfect
must I have reacted? must you have reacted? must she have reacted? must we have reacted? must you have reacted? must they have reacted?
V-ing perfect
must I have been reacting? must you have been reacting? must she have been reacting? must we have been reacting? must you have been reacting? must they have been reacting?
Interro-negative form
Simple form
must I not react? must you not react? must she not react? must we not react? must you not react? must they not react?
V-ing form
must I not be reacting? must you not be reacting? must she not be reacting? must we not be reacting? must you not be reacting? must they not be reacting?
Perfect
must I not have reacted? must you not have reacted? must she not have reacted? must we not have reacted? must you not have reacted? must they not have reacted?
V-ing perfect
must I not have been reacting? must you not have been reacting? must she not have been reacting? must we not have been reacting? must you not have been reacting? must they not have been reacting?