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 couldn't row you couldn't row she couldn't row we couldn't row you couldn't row they couldn't row
V-ing form
I couldn't be rowing you couldn't be rowing she couldn't be rowing we couldn't be rowing you couldn't be rowing they couldn't be rowing
Perfect
I couldn't have rowed you couldn't have rowed she couldn't have rowed we couldn't have rowed you couldn't have rowed they couldn't have rowed
V-ing perfect
I couldn't have been rowing you couldn't have been rowing she couldn't have been rowing we couldn't have been rowing you couldn't have been rowing they couldn't 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
couldn't I row? couldn't you row? couldn't she row? couldn't we row? couldn't you row? couldn't they row?
V-ing form
couldn't I be rowing? couldn't you be rowing? couldn't she be rowing? couldn't we be rowing? couldn't you be rowing? couldn't they be rowing?
Perfect
couldn't I have rowed? couldn't you have rowed? couldn't she have rowed? couldn't we have rowed? couldn't you have rowed? couldn't they have rowed?
V-ing perfect
couldn't I have been rowing? couldn't you have been rowing? couldn't she have been rowing? couldn't we have been rowing? couldn't you have been rowing? couldn't they have been rowing?