Conjugação do verbo inglês
COULD SUM

Verbo regular: sum - summed - summed

Afirmação

Forma simple	Forma com V-ing
I could sum you could sum she could sum we could sum you could sum they could sum	I could be summing you could be summing she could be summing we could be summing you could be summing they could be summing
Perfeito	Perfeito com V-ing
I could have summed you could have summed she could have summed we could have summed you could have summed they could have summed	I could have been summing you could have been summing she could have been summing we could have been summing you could have been summing they could have been summing

Negação

Forma simple	Forma com V-ing
I could not sum you could not sum she could not sum we could not sum you could not sum they could not sum	I could not be summing you could not be summing she could not be summing we could not be summing you could not be summing they could not be summing
Perfeito	Perfeito com V-ing
I could not have summed you could not have summed she could not have summed we could not have summed you could not have summed they could not have summed	I could not have been summing you could not have been summing she could not have been summing we could not have been summing you could not have been summing they could not have been summing

Forma interrogativa

Forma simple	Forma com V-ing
could I sum? could you sum? could she sum? could we sum? could you sum? could they sum?	could I be summing? could you be summing? could she be summing? could we be summing? could you be summing? could they be summing?
Perfeito	Perfeito com V-ing
could I have summed? could you have summed? could she have summed? could we have summed? could you have summed? could they have summed?	could I have been summing? could you have been summing? could she have been summing? could we have been summing? could you have been summing? could they have been summing?

Forma interro-Negação

Forma simple	Forma com V-ing
could I not sum? could you not sum? could she not sum? could we not sum? could you not sum? could they not sum?	could I not be summing? could you not be summing? could she not be summing? could we not be summing? could you not be summing? could they not be summing?
Perfeito	Perfeito com V-ing
could I not have summed? could you not have summed? could she not have summed? could we not have summed? could you not have summed? could they not have summed?	could I not have been summing? could you not have been summing? could she not have been summing? could we not have been summing? could you not have been summing? could they not have been summing?