English verb conjugation
MUST WEAKEN

Regular verb: weaken - weakened - weakened

Affirmation

Simple form	V-ing form
I must weaken you must weaken she must weaken we must weaken you must weaken they must weaken	I must be weakening you must be weakening she must be weakening we must be weakening you must be weakening they must be weakening
Perfect	V-ing perfect
I must have weakened you must have weakened she must have weakened we must have weakened you must have weakened they must have weakened	I must have been weakening you must have been weakening she must have been weakening we must have been weakening you must have been weakening they must have been weakening

Negation

Simple form	V-ing form
I mustn't weaken you mustn't weaken she mustn't weaken we mustn't weaken you mustn't weaken they mustn't weaken	I mustn't be weakening you mustn't be weakening she mustn't be weakening we mustn't be weakening you mustn't be weakening they mustn't be weakening
Perfect	V-ing perfect
I mustn't have weakened you mustn't have weakened she mustn't have weakened we mustn't have weakened you mustn't have weakened they mustn't have weakened	I mustn't have been weakening you mustn't have been weakening she mustn't have been weakening we mustn't have been weakening you mustn't have been weakening they mustn't have been weakening

Interrogative form

Simple form	V-ing form
must I weaken? must you weaken? must she weaken? must we weaken? must you weaken? must they weaken?	must I be weakening? must you be weakening? must she be weakening? must we be weakening? must you be weakening? must they be weakening?
Perfect	V-ing perfect
must I have weakened? must you have weakened? must she have weakened? must we have weakened? must you have weakened? must they have weakened?	must I have been weakening? must you have been weakening? must she have been weakening? must we have been weakening? must you have been weakening? must they have been weakening?

Interro-negative form

Simple form	V-ing form
mustn't I weaken? mustn't you weaken? mustn't she weaken? mustn't we weaken? mustn't you weaken? mustn't they weaken?	mustn't I be weakening? mustn't you be weakening? mustn't she be weakening? mustn't we be weakening? mustn't you be weakening? mustn't they be weakening?
Perfect	V-ing perfect
mustn't I have weakened? mustn't you have weakened? mustn't she have weakened? mustn't we have weakened? mustn't you have weakened? mustn't they have weakened?	mustn't I have been weakening? mustn't you have been weakening? mustn't she have been weakening? mustn't we have been weakening? mustn't you have been weakening? mustn't they have been weakening?