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