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
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	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	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must not weaken
you must not weaken
she must not weaken
we must not weaken
you must not weaken
they must not weaken 	I must not be weakening
you must not be weakening
she must not be weakening
we must not be weakening
you must not be weakening
they must not be weakening	I must not have weakened
you must not have weakened
she must not have weakened
we must not have weakened
you must not have weakened
they must not have weakened	I must not have been weakening
you must not have been weakening
she must not have been weakening
we must not have been weakening
you must not have been weakening
they must not have been weakening	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
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? 	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? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I not weaken?
must you not weaken?
must she not weaken?
must we not weaken?
must you not weaken?
must they not weaken? 	must I not be weakening?
must you not be weakening?
must she not be weakening?
must we not be weakening?
must you not be weakening?
must they not be weakening? 	must I not have weakened?
must you not have weakened?
must she not have weakened?
must we not have weakened?
must you not have weakened?
must they not have weakened? 	must I not have been weakening?
must you not have been weakening?
must she not have been weakening?
must we not have been weakening?
must you not have been weakening?
must they not have been weakening?