I can harp you can harp he can harp we can harp you can harp they can harp
V-ing form
I can be harping you can be harping he can be harping we can be harping you can be harping they can be harping
Perfect
I can have harped you can have harped he can have harped we can have harped you can have harped they can have harped
V-ing perfect
I can have been harping you can have been harping he can have been harping we can have been harping you can have been harping they can have been harping
Negation
Simple form
I cannot harp you cannot harp he cannot harp we cannot harp you cannot harp they cannot harp
V-ing form
I cannot be harping you cannot be harping he cannot be harping we cannot be harping you cannot be harping they cannot be harping
Perfect
I cannot have harped you cannot have harped he cannot have harped we cannot have harped you cannot have harped they cannot have harped
V-ing perfect
I cannot have been harping you cannot have been harping he cannot have been harping we cannot have been harping you cannot have been harping they cannot have been harping
Interrogative form
Simple form
can I harp? can you harp? can he harp? can we harp? can you harp? can they harp?
V-ing form
can I be harping? can you be harping? can he be harping? can we be harping? can you be harping? can they be harping?
Perfect
can I have harped? can you have harped? can he have harped? can we have harped? can you have harped? can they have harped?
V-ing perfect
can I have been harping? can you have been harping? can he have been harping? can we have been harping? can you have been harping? can they have been harping?
Interro-negative form
Simple form
can I not harp? can you not harp? can he not harp? can we not harp? can you not harp? can they not harp?
V-ing form
can I not be harping? can you not be harping? can he not be harping? can we not be harping? can you not be harping? can they not be harping?
Perfect
can I not have harped? can you not have harped? can he not have harped? can we not have harped? can you not have harped? can they not have harped?
V-ing perfect
can I not have been harping? can you not have been harping? can he not have been harping? can we not have been harping? can you not have been harping? can they not have been harping?