I can peck you can peck she can peck we can peck you can peck they can peck
V-ing form
I can be pecking you can be pecking she can be pecking we can be pecking you can be pecking they can be pecking
Perfect
I can have pecked you can have pecked she can have pecked we can have pecked you can have pecked they can have pecked
V-ing perfect
I can have been pecking you can have been pecking she can have been pecking we can have been pecking you can have been pecking they can have been pecking
Negation
Simple form
I cannot peck you cannot peck she cannot peck we cannot peck you cannot peck they cannot peck
V-ing form
I cannot be pecking you cannot be pecking she cannot be pecking we cannot be pecking you cannot be pecking they cannot be pecking
Perfect
I cannot have pecked you cannot have pecked she cannot have pecked we cannot have pecked you cannot have pecked they cannot have pecked
V-ing perfect
I cannot have been pecking you cannot have been pecking she cannot have been pecking we cannot have been pecking you cannot have been pecking they cannot have been pecking
Interrogative form
Simple form
can I peck? can you peck? can she peck? can we peck? can you peck? can they peck?
V-ing form
can I be pecking? can you be pecking? can she be pecking? can we be pecking? can you be pecking? can they be pecking?
Perfect
can I have pecked? can you have pecked? can she have pecked? can we have pecked? can you have pecked? can they have pecked?
V-ing perfect
can I have been pecking? can you have been pecking? can she have been pecking? can we have been pecking? can you have been pecking? can they have been pecking?
Interro-negative form
Simple form
can I not peck? can you not peck? can she not peck? can we not peck? can you not peck? can they not peck?
V-ing form
can I not be pecking? can you not be pecking? can she not be pecking? can we not be pecking? can you not be pecking? can they not be pecking?
Perfect
can I not have pecked? can you not have pecked? can she not have pecked? can we not have pecked? can you not have pecked? can they not have pecked?
V-ing perfect
can I not have been pecking? can you not have been pecking? can she not have been pecking? can we not have been pecking? can you not have been pecking? can they not have been pecking?