I could plaster you could plaster she could plaster we could plaster you could plaster they could plaster
V-ing form
I could be plastering you could be plastering she could be plastering we could be plastering you could be plastering they could be plastering
Perfect
I could have plastered you could have plastered she 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 she 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 she 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 she 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 she 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 she 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 she plaster? could we plaster? could you plaster? could they plaster?
V-ing form
could I be plastering? could you be plastering? could she be plastering? could we be plastering? could you be plastering? could they be plastering?
Perfect
could I have plastered? could you have plastered? could she 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 she 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 she 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 she 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 she 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 she have been plastering? couldn't we have been plastering? couldn't you have been plastering? couldn't they have been plastering?