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 mustn't preserve you mustn't preserve he mustn't preserve we mustn't preserve you mustn't preserve they mustn't preserve	I mustn't be preserving you mustn't be preserving he mustn't be preserving we mustn't be preserving you mustn't be preserving they mustn't be preserving
Perfect	V-ing perfect
I mustn't have preserved you mustn't have preserved he mustn't have preserved we mustn't have preserved you mustn't have preserved they mustn't have preserved	I mustn't have been preserving you mustn't have been preserving he mustn't have been preserving we mustn't have been preserving you mustn't have been preserving they mustn't 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
mustn't I preserve? mustn't you preserve? mustn't he preserve? mustn't we preserve? mustn't you preserve? mustn't they preserve?	mustn't I be preserving? mustn't you be preserving? mustn't he be preserving? mustn't we be preserving? mustn't you be preserving? mustn't they be preserving?
Perfect	V-ing perfect
mustn't I have preserved? mustn't you have preserved? mustn't he have preserved? mustn't we have preserved? mustn't you have preserved? mustn't they have preserved?	mustn't I have been preserving? mustn't you have been preserving? mustn't he have been preserving? mustn't we have been preserving? mustn't you have been preserving? mustn't they have been preserving?