I could skim you could skim she could skim we could skim you could skim they could skim
Forma con V-ing
I could be skimming you could be skimming she could be skimming we could be skimming you could be skimming they could be skimming
Perfecto
I could have skimmed you could have skimmed she could have skimmed we could have skimmed you could have skimmed they could have skimmed
Perfecto con V-ing
I could have been skimming you could have been skimming she could have been skimming we could have been skimming you could have been skimming they could have been skimming
Negación
Forma simple
I could not skim you could not skim she could not skim we could not skim you could not skim they could not skim
Forma con V-ing
I could not be skimming you could not be skimming she could not be skimming we could not be skimming you could not be skimming they could not be skimming
Perfecto
I could not have skimmed you could not have skimmed she could not have skimmed we could not have skimmed you could not have skimmed they could not have skimmed
Perfecto con V-ing
I could not have been skimming you could not have been skimming she could not have been skimming we could not have been skimming you could not have been skimming they could not have been skimming
Forma interrogativa
Forma simple
could I skim? could you skim? could she skim? could we skim? could you skim? could they skim?
Forma con V-ing
could I be skimming? could you be skimming? could she be skimming? could we be skimming? could you be skimming? could they be skimming?
Perfecto
could I have skimmed? could you have skimmed? could she have skimmed? could we have skimmed? could you have skimmed? could they have skimmed?
Perfecto con V-ing
could I have been skimming? could you have been skimming? could she have been skimming? could we have been skimming? could you have been skimming? could they have been skimming?
Forma interro-negativa
Forma simple
could I not skim? could you not skim? could she not skim? could we not skim? could you not skim? could they not skim?
Forma con V-ing
could I not be skimming? could you not be skimming? could she not be skimming? could we not be skimming? could you not be skimming? could they not be skimming?
Perfecto
could I not have skimmed? could you not have skimmed? could she not have skimmed? could we not have skimmed? could you not have skimmed? could they not have skimmed?
Perfecto con V-ing
could I not have been skimming? could you not have been skimming? could she not have been skimming? could we not have been skimming? could you not have been skimming? could they not have been skimming?