I could interest you could interest he could interest we could interest you could interest they could interest
V-ing form
I could be interesting you could be interesting he could be interesting we could be interesting you could be interesting they could be interesting
Perfect
I could have interested you could have interested he 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 he 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 he 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 he 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 he 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 he 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 he interest? could we interest? could you interest? could they interest?
V-ing form
could I be interesting? could you be interesting? could he be interesting? could we be interesting? could you be interesting? could they be interesting?
Perfect
could I have interested? could you have interested? could he 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 he 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 he 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 he 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 he 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 he not have been interesting? could we not have been interesting? could you not have been interesting? could they not have been interesting?