I could row you could row she could row we could row you could row they could row
V-ing form
I could be rowing you could be rowing she could be rowing we could be rowing you could be rowing they could be rowing
Perfect
I could have rowed you could have rowed she could have rowed we could have rowed you could have rowed they could have rowed
V-ing perfect
I could have been rowing you could have been rowing she could have been rowing we could have been rowing you could have been rowing they could have been rowing
Negation
Simple form
I could not row you could not row she could not row we could not row you could not row they could not row
V-ing form
I could not be rowing you could not be rowing she could not be rowing we could not be rowing you could not be rowing they could not be rowing
Perfect
I could not have rowed you could not have rowed she could not have rowed we could not have rowed you could not have rowed they could not have rowed
V-ing perfect
I could not have been rowing you could not have been rowing she could not have been rowing we could not have been rowing you could not have been rowing they could not have been rowing
Interrogative form
Simple form
could I row? could you row? could she row? could we row? could you row? could they row?
V-ing form
could I be rowing? could you be rowing? could she be rowing? could we be rowing? could you be rowing? could they be rowing?
Perfect
could I have rowed? could you have rowed? could she have rowed? could we have rowed? could you have rowed? could they have rowed?
V-ing perfect
could I have been rowing? could you have been rowing? could she have been rowing? could we have been rowing? could you have been rowing? could they have been rowing?
Interro-negative form
Simple form
could I not row? could you not row? could she not row? could we not row? could you not row? could they not row?
V-ing form
could I not be rowing? could you not be rowing? could she not be rowing? could we not be rowing? could you not be rowing? could they not be rowing?
Perfect
could I not have rowed? could you not have rowed? could she not have rowed? could we not have rowed? could you not have rowed? could they not have rowed?
V-ing perfect
could I not have been rowing? could you not have been rowing? could she not have been rowing? could we not have been rowing? could you not have been rowing? could they not have been rowing?