English verb conjugation
COULD SKIM

Regular verb: skim - skimmed - skimmed

Affirmation

Simple form	V-ing form
I could skim you could skim he could skim we could skim you could skim they could skim	I could be skimming you could be skimming he could be skimming we could be skimming you could be skimming they could be skimming
Perfect	V-ing perfect
I could have skimmed you could have skimmed he could have skimmed we could have skimmed you could have skimmed they could have skimmed	I could have been skimming you could have been skimming he could have been skimming we could have been skimming you could have been skimming they could have been skimming

Negation

Simple form	V-ing form
I couldn't skim you couldn't skim he couldn't skim we couldn't skim you couldn't skim they couldn't skim	I couldn't be skimming you couldn't be skimming he couldn't be skimming we couldn't be skimming you couldn't be skimming they couldn't be skimming
Perfect	V-ing perfect
I couldn't have skimmed you couldn't have skimmed he couldn't have skimmed we couldn't have skimmed you couldn't have skimmed they couldn't have skimmed	I couldn't have been skimming you couldn't have been skimming he couldn't have been skimming we couldn't have been skimming you couldn't have been skimming they couldn't have been skimming

Interrogative form

Simple form	V-ing form
could I skim? could you skim? could he skim? could we skim? could you skim? could they skim?	could I be skimming? could you be skimming? could he be skimming? could we be skimming? could you be skimming? could they be skimming?
Perfect	V-ing perfect
could I have skimmed? could you have skimmed? could he have skimmed? could we have skimmed? could you have skimmed? could they have skimmed?	could I have been skimming? could you have been skimming? could he have been skimming? could we have been skimming? could you have been skimming? could they have been skimming?

Interro-negative form

Simple form	V-ing form
couldn't I skim? couldn't you skim? couldn't he skim? couldn't we skim? couldn't you skim? couldn't they skim?	couldn't I be skimming? couldn't you be skimming? couldn't he be skimming? couldn't we be skimming? couldn't you be skimming? couldn't they be skimming?
Perfect	V-ing perfect
couldn't I have skimmed? couldn't you have skimmed? couldn't he have skimmed? couldn't we have skimmed? couldn't you have skimmed? couldn't they have skimmed?	couldn't I have been skimming? couldn't you have been skimming? couldn't he have been skimming? couldn't we have been skimming? couldn't you have been skimming? couldn't they have been skimming?