I could machine-stitch you could machine-stitch he could machine-stitch we could machine-stitch you could machine-stitch they could machine-stitch
V-ing form
I could be machine-stitching you could be machine-stitching he could be machine-stitching we could be machine-stitching you could be machine-stitching they could be machine-stitching
Perfect
I could have machine-stitched you could have machine-stitched he could have machine-stitched we could have machine-stitched you could have machine-stitched they could have machine-stitched
V-ing perfect
I could have been machine-stitching you could have been machine-stitching he could have been machine-stitching we could have been machine-stitching you could have been machine-stitching they could have been machine-stitching
Negation
Simple form
I could not machine-stitch you could not machine-stitch he could not machine-stitch we could not machine-stitch you could not machine-stitch they could not machine-stitch
V-ing form
I could not be machine-stitching you could not be machine-stitching he could not be machine-stitching we could not be machine-stitching you could not be machine-stitching they could not be machine-stitching
Perfect
I could not have machine-stitched you could not have machine-stitched he could not have machine-stitched we could not have machine-stitched you could not have machine-stitched they could not have machine-stitched
V-ing perfect
I could not have been machine-stitching you could not have been machine-stitching he could not have been machine-stitching we could not have been machine-stitching you could not have been machine-stitching they could not have been machine-stitching
Interrogative form
Simple form
could I machine-stitch? could you machine-stitch? could he machine-stitch? could we machine-stitch? could you machine-stitch? could they machine-stitch?
V-ing form
could I be machine-stitching? could you be machine-stitching? could he be machine-stitching? could we be machine-stitching? could you be machine-stitching? could they be machine-stitching?
Perfect
could I have machine-stitched? could you have machine-stitched? could he have machine-stitched? could we have machine-stitched? could you have machine-stitched? could they have machine-stitched?
V-ing perfect
could I have been machine-stitching? could you have been machine-stitching? could he have been machine-stitching? could we have been machine-stitching? could you have been machine-stitching? could they have been machine-stitching?
Interro-negative form
Simple form
could I not machine-stitch? could you not machine-stitch? could he not machine-stitch? could we not machine-stitch? could you not machine-stitch? could they not machine-stitch?
V-ing form
could I not be machine-stitching? could you not be machine-stitching? could he not be machine-stitching? could we not be machine-stitching? could you not be machine-stitching? could they not be machine-stitching?
Perfect
could I not have machine-stitched? could you not have machine-stitched? could he not have machine-stitched? could we not have machine-stitched? could you not have machine-stitched? could they not have machine-stitched?
V-ing perfect
could I not have been machine-stitching? could you not have been machine-stitching? could he not have been machine-stitching? could we not have been machine-stitching? could you not have been machine-stitching? could they not have been machine-stitching?