I could harp you could harp she could harp we could harp you could harp they could harp
V-ing form
I could be harping you could be harping she could be harping we could be harping you could be harping they could be harping
Perfect
I could have harped you could have harped she could have harped we could have harped you could have harped they could have harped
V-ing perfect
I could have been harping you could have been harping she could have been harping we could have been harping you could have been harping they could have been harping
Negation
Simple form
I couldn't harp you couldn't harp she couldn't harp we couldn't harp you couldn't harp they couldn't harp
V-ing form
I couldn't be harping you couldn't be harping she couldn't be harping we couldn't be harping you couldn't be harping they couldn't be harping
Perfect
I couldn't have harped you couldn't have harped she couldn't have harped we couldn't have harped you couldn't have harped they couldn't have harped
V-ing perfect
I couldn't have been harping you couldn't have been harping she couldn't have been harping we couldn't have been harping you couldn't have been harping they couldn't have been harping
Interrogative form
Simple form
could I harp? could you harp? could she harp? could we harp? could you harp? could they harp?
V-ing form
could I be harping? could you be harping? could she be harping? could we be harping? could you be harping? could they be harping?
Perfect
could I have harped? could you have harped? could she have harped? could we have harped? could you have harped? could they have harped?
V-ing perfect
could I have been harping? could you have been harping? could she have been harping? could we have been harping? could you have been harping? could they have been harping?
Interro-negative form
Simple form
couldn't I harp? couldn't you harp? couldn't she harp? couldn't we harp? couldn't you harp? couldn't they harp?
V-ing form
couldn't I be harping? couldn't you be harping? couldn't she be harping? couldn't we be harping? couldn't you be harping? couldn't they be harping?
Perfect
couldn't I have harped? couldn't you have harped? couldn't she have harped? couldn't we have harped? couldn't you have harped? couldn't they have harped?
V-ing perfect
couldn't I have been harping? couldn't you have been harping? couldn't she have been harping? couldn't we have been harping? couldn't you have been harping? couldn't they have been harping?