I could sow you could sow he could sow we could sow you could sow they could sow
V-ing form
I could be sowing you could be sowing he could be sowing we could be sowing you could be sowing they could be sowing
Perfect
I could have sown, sowed you could have sown, sowed he could have sown, sowed we could have sown, sowed you could have sown, sowed they could have sown, sowed
V-ing perfect
I could have been sowing you could have been sowing he could have been sowing we could have been sowing you could have been sowing they could have been sowing
Negation
Simple form
I could not sow you could not sow he could not sow we could not sow you could not sow they could not sow
V-ing form
I could not be sowing you could not be sowing he could not be sowing we could not be sowing you could not be sowing they could not be sowing
Perfect
I could not have sown, sowed you could not have sown, sowed he could not have sown, sowed we could not have sown, sowed you could not have sown, sowed they could not have sown, sowed
V-ing perfect
I could not have been sowing you could not have been sowing he could not have been sowing we could not have been sowing you could not have been sowing they could not have been sowing
Interrogative form
Simple form
could I sow? could you sow? could he sow? could we sow? could you sow? could they sow?
V-ing form
could I be sowing? could you be sowing? could he be sowing? could we be sowing? could you be sowing? could they be sowing?
Perfect
could I have sown, sowed? could you have sown, sowed? could he have sown, sowed? could we have sown, sowed? could you have sown, sowed? could they have sown, sowed?
V-ing perfect
could I have been sowing? could you have been sowing? could he have been sowing? could we have been sowing? could you have been sowing? could they have been sowing?
Interro-negative form
Simple form
could I not sow? could you not sow? could he not sow? could we not sow? could you not sow? could they not sow?
V-ing form
could I not be sowing? could you not be sowing? could he not be sowing? could we not be sowing? could you not be sowing? could they not be sowing?
Perfect
could I not have sown, sowed? could you not have sown, sowed? could he not have sown, sowed? could we not have sown, sowed? could you not have sown, sowed? could they not have sown, sowed?
V-ing perfect
could I not have been sowing? could you not have been sowing? could he not have been sowing? could we not have been sowing? could you not have been sowing? could they not have been sowing?