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