I could confer you could confer he could confer we could confer you could confer they could confer
V-ing form
I could be conferring you could be conferring he could be conferring we could be conferring you could be conferring they could be conferring
Perfect
I could have conferred you could have conferred he could have conferred we could have conferred you could have conferred they could have conferred
V-ing perfect
I could have been conferring you could have been conferring he could have been conferring we could have been conferring you could have been conferring they could have been conferring
Negation
Simple form
I could not confer you could not confer he could not confer we could not confer you could not confer they could not confer
V-ing form
I could not be conferring you could not be conferring he could not be conferring we could not be conferring you could not be conferring they could not be conferring
Perfect
I could not have conferred you could not have conferred he could not have conferred we could not have conferred you could not have conferred they could not have conferred
V-ing perfect
I could not have been conferring you could not have been conferring he could not have been conferring we could not have been conferring you could not have been conferring they could not have been conferring
Interrogative form
Simple form
could I confer? could you confer? could he confer? could we confer? could you confer? could they confer?
V-ing form
could I be conferring? could you be conferring? could he be conferring? could we be conferring? could you be conferring? could they be conferring?
Perfect
could I have conferred? could you have conferred? could he have conferred? could we have conferred? could you have conferred? could they have conferred?
V-ing perfect
could I have been conferring? could you have been conferring? could he have been conferring? could we have been conferring? could you have been conferring? could they have been conferring?
Interro-negative form
Simple form
could I not confer? could you not confer? could he not confer? could we not confer? could you not confer? could they not confer?
V-ing form
could I not be conferring? could you not be conferring? could he not be conferring? could we not be conferring? could you not be conferring? could they not be conferring?
Perfect
could I not have conferred? could you not have conferred? could he not have conferred? could we not have conferred? could you not have conferred? could they not have conferred?
V-ing perfect
could I not have been conferring? could you not have been conferring? could he not have been conferring? could we not have been conferring? could you not have been conferring? could they not have been conferring?