I could degrease you could degrease he could degrease we could degrease you could degrease they could degrease
V-ing form
I could be degreasing you could be degreasing he could be degreasing we could be degreasing you could be degreasing they could be degreasing
Perfect
I could have degreased you could have degreased he could have degreased we could have degreased you could have degreased they could have degreased
V-ing perfect
I could have been degreasing you could have been degreasing he could have been degreasing we could have been degreasing you could have been degreasing they could have been degreasing
Negation
Simple form
I could not degrease you could not degrease he could not degrease we could not degrease you could not degrease they could not degrease
V-ing form
I could not be degreasing you could not be degreasing he could not be degreasing we could not be degreasing you could not be degreasing they could not be degreasing
Perfect
I could not have degreased you could not have degreased he could not have degreased we could not have degreased you could not have degreased they could not have degreased
V-ing perfect
I could not have been degreasing you could not have been degreasing he could not have been degreasing we could not have been degreasing you could not have been degreasing they could not have been degreasing
Interrogative form
Simple form
could I degrease? could you degrease? could he degrease? could we degrease? could you degrease? could they degrease?
V-ing form
could I be degreasing? could you be degreasing? could he be degreasing? could we be degreasing? could you be degreasing? could they be degreasing?
Perfect
could I have degreased? could you have degreased? could he have degreased? could we have degreased? could you have degreased? could they have degreased?
V-ing perfect
could I have been degreasing? could you have been degreasing? could he have been degreasing? could we have been degreasing? could you have been degreasing? could they have been degreasing?
Interro-negative form
Simple form
could I not degrease? could you not degrease? could he not degrease? could we not degrease? could you not degrease? could they not degrease?
V-ing form
could I not be degreasing? could you not be degreasing? could he not be degreasing? could we not be degreasing? could you not be degreasing? could they not be degreasing?
Perfect
could I not have degreased? could you not have degreased? could he not have degreased? could we not have degreased? could you not have degreased? could they not have degreased?
V-ing perfect
could I not have been degreasing? could you not have been degreasing? could he not have been degreasing? could we not have been degreasing? could you not have been degreasing? could they not have been degreasing?