could worsen
Verbo regular: worsen - worsened- worsened

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could worsen
you could worsen
he could worsen
we could worsen
you could worsen
they could worsen 	I could be worsening
you could be worsening
he could be worsening
we could be worsening
you could be worsening
they could be worsening	I could have worsened
you could have worsened
he could have worsened
we could have worsened
you could have worsened
they could have worsened	I could have been worsening
you could have been worsening
he could have been worsening
we could have been worsening
you could have been worsening
they could have been worsening	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I couldn't worsen
you couldn't worsen
he couldn't worsen
we couldn't worsen
you couldn't worsen
they couldn't worsen 	I couldn't be worsening
you couldn't be worsening
he couldn't be worsening
we couldn't be worsening
you couldn't be worsening
they couldn't be worsening	I couldn't have worsened
you couldn't have worsened
he couldn't have worsened
we couldn't have worsened
you couldn't have worsened
they couldn't have worsened	I couldn't have been worsening
you couldn't have been worsening
he couldn't have been worsening
we couldn't have been worsening
you couldn't have been worsening
they couldn't have been worsening	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I worsen?
could you worsen?
could he worsen?
could we worsen?
could you worsen?
could they worsen? 	could I be worsening?
could you be worsening?
could he be worsening?
could we be worsening?
could you be worsening?
could they be worsening? 	could I have worsened?
could you have worsened?
could he have worsened?
could we have worsened?
could you have worsened?
could they have worsened? 	could I have been worsening?
could you have been worsening?
could he have been worsening?
could we have been worsening?
could you have been worsening?
could they have been worsening? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
couldn't I worsen?
couldn't you worsen?
couldn't he worsen?
couldn't we worsen?
couldn't you worsen?
couldn't they worsen? 	couldn't I be worsening?
couldn't you be worsening?
couldn't he be worsening?
couldn't we be worsening?
couldn't you be worsening?
couldn't they be worsening? 	couldn't I have worsened?
couldn't you have worsened?
couldn't he have worsened?
couldn't we have worsened?
couldn't you have worsened?
couldn't they have worsened? 	couldn't I have been worsening?
couldn't you have been worsening?
couldn't he have been worsening?
couldn't we have been worsening?
couldn't you have been worsening?
couldn't they have been worsening?