I could backstitch you could backstitch he could backstitch we could backstitch you could backstitch they could backstitch
V-ing form
I could be backstitching you could be backstitching he could be backstitching we could be backstitching you could be backstitching they could be backstitching
Perfect
I could have backstitched you could have backstitched he could have backstitched we could have backstitched you could have backstitched they could have backstitched
V-ing perfect
I could have been backstitching you could have been backstitching he could have been backstitching we could have been backstitching you could have been backstitching they could have been backstitching
Negation
Simple form
I could not backstitch you could not backstitch he could not backstitch we could not backstitch you could not backstitch they could not backstitch
V-ing form
I could not be backstitching you could not be backstitching he could not be backstitching we could not be backstitching you could not be backstitching they could not be backstitching
Perfect
I could not have backstitched you could not have backstitched he could not have backstitched we could not have backstitched you could not have backstitched they could not have backstitched
V-ing perfect
I could not have been backstitching you could not have been backstitching he could not have been backstitching we could not have been backstitching you could not have been backstitching they could not have been backstitching
Interrogative form
Simple form
could I backstitch? could you backstitch? could he backstitch? could we backstitch? could you backstitch? could they backstitch?
V-ing form
could I be backstitching? could you be backstitching? could he be backstitching? could we be backstitching? could you be backstitching? could they be backstitching?
Perfect
could I have backstitched? could you have backstitched? could he have backstitched? could we have backstitched? could you have backstitched? could they have backstitched?
V-ing perfect
could I have been backstitching? could you have been backstitching? could he have been backstitching? could we have been backstitching? could you have been backstitching? could they have been backstitching?
Interro-negative form
Simple form
could I not backstitch? could you not backstitch? could he not backstitch? could we not backstitch? could you not backstitch? could they not backstitch?
V-ing form
could I not be backstitching? could you not be backstitching? could he not be backstitching? could we not be backstitching? could you not be backstitching? could they not be backstitching?
Perfect
could I not have backstitched? could you not have backstitched? could he not have backstitched? could we not have backstitched? could you not have backstitched? could they not have backstitched?
V-ing perfect
could I not have been backstitching? could you not have been backstitching? could he not have been backstitching? could we not have been backstitching? could you not have been backstitching? could they not have been backstitching?