I could snowplough you could snowplough he could snowplough we could snowplough you could snowplough they could snowplough
V-ing form
I could be snowploughing you could be snowploughing he could be snowploughing we could be snowploughing you could be snowploughing they could be snowploughing
Perfect
I could have snowploughed you could have snowploughed he could have snowploughed we could have snowploughed you could have snowploughed they could have snowploughed
V-ing perfect
I could have been snowploughing you could have been snowploughing he could have been snowploughing we could have been snowploughing you could have been snowploughing they could have been snowploughing
Negation
Simple form
I could not snowplough you could not snowplough he could not snowplough we could not snowplough you could not snowplough they could not snowplough
V-ing form
I could not be snowploughing you could not be snowploughing he could not be snowploughing we could not be snowploughing you could not be snowploughing they could not be snowploughing
Perfect
I could not have snowploughed you could not have snowploughed he could not have snowploughed we could not have snowploughed you could not have snowploughed they could not have snowploughed
V-ing perfect
I could not have been snowploughing you could not have been snowploughing he could not have been snowploughing we could not have been snowploughing you could not have been snowploughing they could not have been snowploughing
Interrogative form
Simple form
could I snowplough? could you snowplough? could he snowplough? could we snowplough? could you snowplough? could they snowplough?
V-ing form
could I be snowploughing? could you be snowploughing? could he be snowploughing? could we be snowploughing? could you be snowploughing? could they be snowploughing?
Perfect
could I have snowploughed? could you have snowploughed? could he have snowploughed? could we have snowploughed? could you have snowploughed? could they have snowploughed?
V-ing perfect
could I have been snowploughing? could you have been snowploughing? could he have been snowploughing? could we have been snowploughing? could you have been snowploughing? could they have been snowploughing?
Interro-negative form
Simple form
could I not snowplough? could you not snowplough? could he not snowplough? could we not snowplough? could you not snowplough? could they not snowplough?
V-ing form
could I not be snowploughing? could you not be snowploughing? could he not be snowploughing? could we not be snowploughing? could you not be snowploughing? could they not be snowploughing?
Perfect
could I not have snowploughed? could you not have snowploughed? could he not have snowploughed? could we not have snowploughed? could you not have snowploughed? could they not have snowploughed?
V-ing perfect
could I not have been snowploughing? could you not have been snowploughing? could he not have been snowploughing? could we not have been snowploughing? could you not have been snowploughing? could they not have been snowploughing?