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