I could fix you could fix he could fix we could fix you could fix they could fix
V-ing form
I could be fixing you could be fixing he could be fixing we could be fixing you could be fixing they could be fixing
Perfect
I could have fixed you could have fixed he 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 he could have been fixing we could have been fixing you could have been fixing they could have been fixing
Negation
Simple form
I could not fix you could not fix he could not fix we could not fix you could not fix they could not fix
V-ing form
I could not be fixing you could not be fixing he could not be fixing we could not be fixing you could not be fixing they could not be fixing
Perfect
I could not have fixed you could not have fixed he could not have fixed we could not have fixed you could not have fixed they could not have fixed
V-ing perfect
I could not have been fixing you could not have been fixing he could not have been fixing we could not have been fixing you could not have been fixing they could not have been fixing
Interrogative form
Simple form
could I fix? could you fix? could he fix? could we fix? could you fix? could they fix?
V-ing form
could I be fixing? could you be fixing? could he be fixing? could we be fixing? could you be fixing? could they be fixing?
Perfect
could I have fixed? could you have fixed? could he 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 he have been fixing? could we have been fixing? could you have been fixing? could they have been fixing?
Interro-negative form
Simple form
could I not fix? could you not fix? could he not fix? could we not fix? could you not fix? could they not fix?
V-ing form
could I not be fixing? could you not be fixing? could he not be fixing? could we not be fixing? could you not be fixing? could they not be fixing?
Perfect
could I not have fixed? could you not have fixed? could he not have fixed? could we not have fixed? could you not have fixed? could they not have fixed?
V-ing perfect
could I not have been fixing? could you not have been fixing? could he not have been fixing? could we not have been fixing? could you not have been fixing? could they not have been fixing?