English verb conjugation
MUST PRESERVE

Regular verb: preserve - preserved - preserved

Affirmation

Simple form	V-ing form
I must preserve you must preserve he must preserve we must preserve you must preserve they must preserve	I must be preserving you must be preserving he must be preserving we must be preserving you must be preserving they must be preserving
Perfect	V-ing perfect
I must have preserved you must have preserved he must have preserved we must have preserved you must have preserved they must have preserved	I must have been preserving you must have been preserving he must have been preserving we must have been preserving you must have been preserving they must have been preserving

Negation

Simple form	V-ing form
I must not preserve you must not preserve he must not preserve we must not preserve you must not preserve they must not preserve	I must not be preserving you must not be preserving he must not be preserving we must not be preserving you must not be preserving they must not be preserving
Perfect	V-ing perfect
I must not have preserved you must not have preserved he must not have preserved we must not have preserved you must not have preserved they must not have preserved	I must not have been preserving you must not have been preserving he must not have been preserving we must not have been preserving you must not have been preserving they must not have been preserving

Interrogative form

Simple form	V-ing form
must I preserve? must you preserve? must he preserve? must we preserve? must you preserve? must they preserve?	must I be preserving? must you be preserving? must he be preserving? must we be preserving? must you be preserving? must they be preserving?
Perfect	V-ing perfect
must I have preserved? must you have preserved? must he have preserved? must we have preserved? must you have preserved? must they have preserved?	must I have been preserving? must you have been preserving? must he have been preserving? must we have been preserving? must you have been preserving? must they have been preserving?

Interro-negative form

Simple form	V-ing form
must I not preserve? must you not preserve? must he not preserve? must we not preserve? must you not preserve? must they not preserve?	must I not be preserving? must you not be preserving? must he not be preserving? must we not be preserving? must you not be preserving? must they not be preserving?
Perfect	V-ing perfect
must I not have preserved? must you not have preserved? must he not have preserved? must we not have preserved? must you not have preserved? must they not have preserved?	must I not have been preserving? must you not have been preserving? must he not have been preserving? must we not have been preserving? must you not have been preserving? must they not have been preserving?