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 couldn't skim you couldn't skim she couldn't skim we couldn't skim you couldn't skim they couldn't skim
Forma con V-ing
I couldn't be skimming you couldn't be skimming she couldn't be skimming we couldn't be skimming you couldn't be skimming they couldn't be skimming
Perfecto
I couldn't have skimmed you couldn't have skimmed she couldn't have skimmed we couldn't have skimmed you couldn't have skimmed they couldn't have skimmed
Perfecto con V-ing
I couldn't have been skimming you couldn't have been skimming she couldn't have been skimming we couldn't have been skimming you couldn't have been skimming they couldn't 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
couldn't I skim? couldn't you skim? couldn't she skim? couldn't we skim? couldn't you skim? couldn't they skim?
Forma con V-ing
couldn't I be skimming? couldn't you be skimming? couldn't she be skimming? couldn't we be skimming? couldn't you be skimming? couldn't they be skimming?
Perfecto
couldn't I have skimmed? couldn't you have skimmed? couldn't she have skimmed? couldn't we have skimmed? couldn't you have skimmed? couldn't they have skimmed?
Perfecto con V-ing
couldn't I have been skimming? couldn't you have been skimming? couldn't she have been skimming? couldn't we have been skimming? couldn't you have been skimming? couldn't they have been skimming?