must weaken
Verbo regular: weaken - weakened- weakened

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must weaken
you must weaken
he must weaken
we must weaken
you must weaken
they must weaken 	I must be weakening
you must be weakening
he must be weakening
we must be weakening
you must be weakening
they must be weakening	I must have weakened
you must have weakened
he 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
he must have been weakening
we must have been weakening
you must have been weakening
they must have been weakening	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I mustn't weaken
you mustn't weaken
he 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
he mustn't be weakening
we mustn't be weakening
you mustn't be weakening
they mustn't be weakening	I mustn't have weakened
you mustn't have weakened
he 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
he mustn't have been weakening
we mustn't have been weakening
you mustn't have been weakening
they mustn't have been weakening	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I weaken?
must you weaken?
must he weaken?
must we weaken?
must you weaken?
must they weaken? 	must I be weakening?
must you be weakening?
must he be weakening?
must we be weakening?
must you be weakening?
must they be weakening? 	must I have weakened?
must you have weakened?
must he 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 he have been weakening?
must we have been weakening?
must you have been weakening?
must they have been weakening? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
mustn't I weaken?
mustn't you weaken?
mustn't he 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 he be weakening?
mustn't we be weakening?
mustn't you be weakening?
mustn't they be weakening? 	mustn't I have weakened?
mustn't you have weakened?
mustn't he 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 he have been weakening?
mustn't we have been weakening?
mustn't you have been weakening?
mustn't they have been weakening?