I could interest you could interest she could interest we could interest you could interest they could interest
V-ing form
I could be interesting you could be interesting she could be interesting we could be interesting you could be interesting they could be interesting
Perfect
I could have interested you could have interested she could have interested we could have interested you could have interested they could have interested
V-ing perfect
I could have been interesting you could have been interesting she could have been interesting we could have been interesting you could have been interesting they could have been interesting
Negation
Simple form
I could not interest you could not interest she could not interest we could not interest you could not interest they could not interest
V-ing form
I could not be interesting you could not be interesting she could not be interesting we could not be interesting you could not be interesting they could not be interesting
Perfect
I could not have interested you could not have interested she could not have interested we could not have interested you could not have interested they could not have interested
V-ing perfect
I could not have been interesting you could not have been interesting she could not have been interesting we could not have been interesting you could not have been interesting they could not have been interesting
Interrogative form
Simple form
could I interest? could you interest? could she interest? could we interest? could you interest? could they interest?
V-ing form
could I be interesting? could you be interesting? could she be interesting? could we be interesting? could you be interesting? could they be interesting?
Perfect
could I have interested? could you have interested? could she have interested? could we have interested? could you have interested? could they have interested?
V-ing perfect
could I have been interesting? could you have been interesting? could she have been interesting? could we have been interesting? could you have been interesting? could they have been interesting?
Interro-negative form
Simple form
could I not interest? could you not interest? could she not interest? could we not interest? could you not interest? could they not interest?
V-ing form
could I not be interesting? could you not be interesting? could she not be interesting? could we not be interesting? could you not be interesting? could they not be interesting?
Perfect
could I not have interested? could you not have interested? could she not have interested? could we not have interested? could you not have interested? could they not have interested?
V-ing perfect
could I not have been interesting? could you not have been interesting? could she not have been interesting? could we not have been interesting? could you not have been interesting? could they not have been interesting?