English verb conjugation
MUST RETROACT

Regular verb: retroact - retroacted - retroacted

Affirmation

Simple form	V-ing form
I must retroact you must retroact he must retroact we must retroact you must retroact they must retroact	I must be retroacting you must be retroacting he must be retroacting we must be retroacting you must be retroacting they must be retroacting
Perfect	V-ing perfect
I must have retroacted you must have retroacted he must have retroacted we must have retroacted you must have retroacted they must have retroacted	I must have been retroacting you must have been retroacting he must have been retroacting we must have been retroacting you must have been retroacting they must have been retroacting

Negation

Simple form	V-ing form
I must not retroact you must not retroact he must not retroact we must not retroact you must not retroact they must not retroact	I must not be retroacting you must not be retroacting he must not be retroacting we must not be retroacting you must not be retroacting they must not be retroacting
Perfect	V-ing perfect
I must not have retroacted you must not have retroacted he must not have retroacted we must not have retroacted you must not have retroacted they must not have retroacted	I must not have been retroacting you must not have been retroacting he must not have been retroacting we must not have been retroacting you must not have been retroacting they must not have been retroacting

Interrogative form

Simple form	V-ing form
must I retroact? must you retroact? must he retroact? must we retroact? must you retroact? must they retroact?	must I be retroacting? must you be retroacting? must he be retroacting? must we be retroacting? must you be retroacting? must they be retroacting?
Perfect	V-ing perfect
must I have retroacted? must you have retroacted? must he have retroacted? must we have retroacted? must you have retroacted? must they have retroacted?	must I have been retroacting? must you have been retroacting? must he have been retroacting? must we have been retroacting? must you have been retroacting? must they have been retroacting?

Interro-negative form

Simple form	V-ing form
must I not retroact? must you not retroact? must he not retroact? must we not retroact? must you not retroact? must they not retroact?	must I not be retroacting? must you not be retroacting? must he not be retroacting? must we not be retroacting? must you not be retroacting? must they not be retroacting?
Perfect	V-ing perfect
must I not have retroacted? must you not have retroacted? must he not have retroacted? must we not have retroacted? must you not have retroacted? must they not have retroacted?	must I not have been retroacting? must you not have been retroacting? must he not have been retroacting? must we not have been retroacting? must you not have been retroacting? must they not have been retroacting?