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