English verb conjugation
MUST PRESERVE

Regular verb: preserve - preserved - preserved

Affirmation

Simple form	V-ing form
I must preserve you must preserve she must preserve we must preserve you must preserve they must preserve	I must be preserving you must be preserving she 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 she 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 she 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 she 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 she 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 she 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 she 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 she preserve? must we preserve? must you preserve? must they preserve?	must I be preserving? must you be preserving? must she 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 she 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 she 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 she 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 she 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 she 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 she have been preserving? mustn't we have been preserving? mustn't you have been preserving? mustn't they have been preserving?