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