I could show you could show he could show we could show you could show they could show
V-ing form
I could be showing you could be showing he could be showing we could be showing you could be showing they could be showing
Perfect
I could have shown you could have shown he could have shown we could have shown you could have shown they could have shown
V-ing perfect
I could have been showing you could have been showing he could have been showing we could have been showing you could have been showing they could have been showing
Negation
Simple form
I couldn't show you couldn't show he couldn't show we couldn't show you couldn't show they couldn't show
V-ing form
I couldn't be showing you couldn't be showing he couldn't be showing we couldn't be showing you couldn't be showing they couldn't be showing
Perfect
I couldn't have shown you couldn't have shown he couldn't have shown we couldn't have shown you couldn't have shown they couldn't have shown
V-ing perfect
I couldn't have been showing you couldn't have been showing he couldn't have been showing we couldn't have been showing you couldn't have been showing they couldn't have been showing
Interrogative form
Simple form
could I show? could you show? could he show? could we show? could you show? could they show?
V-ing form
could I be showing? could you be showing? could he be showing? could we be showing? could you be showing? could they be showing?
Perfect
could I have shown? could you have shown? could he have shown? could we have shown? could you have shown? could they have shown?
V-ing perfect
could I have been showing? could you have been showing? could he have been showing? could we have been showing? could you have been showing? could they have been showing?
Interro-negative form
Simple form
couldn't I show? couldn't you show? couldn't he show? couldn't we show? couldn't you show? couldn't they show?
V-ing form
couldn't I be showing? couldn't you be showing? couldn't he be showing? couldn't we be showing? couldn't you be showing? couldn't they be showing?
Perfect
couldn't I have shown? couldn't you have shown? couldn't he have shown? couldn't we have shown? couldn't you have shown? couldn't they have shown?
V-ing perfect
couldn't I have been showing? couldn't you have been showing? couldn't he have been showing? couldn't we have been showing? couldn't you have been showing? couldn't they have been showing?