I could nest you could nest she could nest we could nest you could nest they could nest
V-ing form
I could be nesting you could be nesting she could be nesting we could be nesting you could be nesting they could be nesting
Perfect
I could have nested you could have nested she could have nested we could have nested you could have nested they could have nested
V-ing perfect
I could have been nesting you could have been nesting she could have been nesting we could have been nesting you could have been nesting they could have been nesting
Negation
Simple form
I could not nest you could not nest she could not nest we could not nest you could not nest they could not nest
V-ing form
I could not be nesting you could not be nesting she could not be nesting we could not be nesting you could not be nesting they could not be nesting
Perfect
I could not have nested you could not have nested she could not have nested we could not have nested you could not have nested they could not have nested
V-ing perfect
I could not have been nesting you could not have been nesting she could not have been nesting we could not have been nesting you could not have been nesting they could not have been nesting
Interrogative form
Simple form
could I nest? could you nest? could she nest? could we nest? could you nest? could they nest?
V-ing form
could I be nesting? could you be nesting? could she be nesting? could we be nesting? could you be nesting? could they be nesting?
Perfect
could I have nested? could you have nested? could she have nested? could we have nested? could you have nested? could they have nested?
V-ing perfect
could I have been nesting? could you have been nesting? could she have been nesting? could we have been nesting? could you have been nesting? could they have been nesting?
Interro-negative form
Simple form
could I not nest? could you not nest? could she not nest? could we not nest? could you not nest? could they not nest?
V-ing form
could I not be nesting? could you not be nesting? could she not be nesting? could we not be nesting? could you not be nesting? could they not be nesting?
Perfect
could I not have nested? could you not have nested? could she not have nested? could we not have nested? could you not have nested? could they not have nested?
V-ing perfect
could I not have been nesting? could you not have been nesting? could she not have been nesting? could we not have been nesting? could you not have been nesting? could they not have been nesting?