I could paint you could paint she could paint we could paint you could paint they could paint
V-ing form
I could be painting you could be painting she could be painting we could be painting you could be painting they could be painting
Perfect
I could have painted you could have painted she could have painted we could have painted you could have painted they could have painted
V-ing perfect
I could have been painting you could have been painting she could have been painting we could have been painting you could have been painting they could have been painting
Negation
Simple form
I couldn't paint you couldn't paint she couldn't paint we couldn't paint you couldn't paint they couldn't paint
V-ing form
I couldn't be painting you couldn't be painting she couldn't be painting we couldn't be painting you couldn't be painting they couldn't be painting
Perfect
I couldn't have painted you couldn't have painted she couldn't have painted we couldn't have painted you couldn't have painted they couldn't have painted
V-ing perfect
I couldn't have been painting you couldn't have been painting she couldn't have been painting we couldn't have been painting you couldn't have been painting they couldn't have been painting
Interrogative form
Simple form
could I paint? could you paint? could she paint? could we paint? could you paint? could they paint?
V-ing form
could I be painting? could you be painting? could she be painting? could we be painting? could you be painting? could they be painting?
Perfect
could I have painted? could you have painted? could she have painted? could we have painted? could you have painted? could they have painted?
V-ing perfect
could I have been painting? could you have been painting? could she have been painting? could we have been painting? could you have been painting? could they have been painting?
Interro-negative form
Simple form
couldn't I paint? couldn't you paint? couldn't she paint? couldn't we paint? couldn't you paint? couldn't they paint?
V-ing form
couldn't I be painting? couldn't you be painting? couldn't she be painting? couldn't we be painting? couldn't you be painting? couldn't they be painting?
Perfect
couldn't I have painted? couldn't you have painted? couldn't she have painted? couldn't we have painted? couldn't you have painted? couldn't they have painted?
V-ing perfect
couldn't I have been painting? couldn't you have been painting? couldn't she have been painting? couldn't we have been painting? couldn't you have been painting? couldn't they have been painting?