can weaken
Verbo regular: weaken - weakened- weakened

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I can weaken
you can weaken
he can weaken
we can weaken
you can weaken
they can weaken 	I can be weakening
you can be weakening
he can be weakening
we can be weakening
you can be weakening
they can be weakening	I can have weakened
you can have weakened
he can have weakened
we can have weakened
you can have weakened
they can have weakened	I can have been weakening
you can have been weakening
he can have been weakening
we can have been weakening
you can have been weakening
they can have been weakening	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I can't weaken
you can't weaken
he can't weaken
we can't weaken
you can't weaken
they can't weaken 	I can't be weakening
you can't be weakening
he can't be weakening
we can't be weakening
you can't be weakening
they can't be weakening	I can't have weakened
you can't have weakened
he can't have weakened
we can't have weakened
you can't have weakened
they can't have weakened	I can't have been weakening
you can't have been weakening
he can't have been weakening
we can't have been weakening
you can't have been weakening
they can't have been weakening	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
can I weaken?
can you weaken?
can he weaken?
can we weaken?
can you weaken?
can they weaken? 	can I be weakening?
can you be weakening?
can he be weakening?
can we be weakening?
can you be weakening?
can they be weakening? 	can I have weakened?
can you have weakened?
can he have weakened?
can we have weakened?
can you have weakened?
can they have weakened? 	can I have been weakening?
can you have been weakening?
can he have been weakening?
can we have been weakening?
can you have been weakening?
can they have been weakening? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
can't I weaken?
can't you weaken?
can't he weaken?
can't we weaken?
can't you weaken?
can't they weaken? 	can't I be weakening?
can't you be weakening?
can't he be weakening?
can't we be weakening?
can't you be weakening?
can't they be weakening? 	can't I have weakened?
can't you have weakened?
can't he have weakened?
can't we have weakened?
can't you have weakened?
can't they have weakened? 	can't I have been weakening?
can't you have been weakening?
can't he have been weakening?
can't we have been weakening?
can't you have been weakening?
can't they have been weakening?