I could confer you could confer she could confer we could confer you could confer they could confer
V-ing form
I could be conferring you could be conferring she could be conferring we could be conferring you could be conferring they could be conferring
Perfect
I could have conferred you could have conferred she 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 she could have been conferring we could have been conferring you could have been conferring they could have been conferring
Negation
Simple form
I couldn't confer you couldn't confer she couldn't confer we couldn't confer you couldn't confer they couldn't confer
V-ing form
I couldn't be conferring you couldn't be conferring she couldn't be conferring we couldn't be conferring you couldn't be conferring they couldn't be conferring
Perfect
I couldn't have conferred you couldn't have conferred she couldn't have conferred we couldn't have conferred you couldn't have conferred they couldn't have conferred
V-ing perfect
I couldn't have been conferring you couldn't have been conferring she couldn't have been conferring we couldn't have been conferring you couldn't have been conferring they couldn't have been conferring
Interrogative form
Simple form
could I confer? could you confer? could she confer? could we confer? could you confer? could they confer?
V-ing form
could I be conferring? could you be conferring? could she be conferring? could we be conferring? could you be conferring? could they be conferring?
Perfect
could I have conferred? could you have conferred? could she 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 she have been conferring? could we have been conferring? could you have been conferring? could they have been conferring?
Interro-negative form
Simple form
couldn't I confer? couldn't you confer? couldn't she confer? couldn't we confer? couldn't you confer? couldn't they confer?
V-ing form
couldn't I be conferring? couldn't you be conferring? couldn't she be conferring? couldn't we be conferring? couldn't you be conferring? couldn't they be conferring?
Perfect
couldn't I have conferred? couldn't you have conferred? couldn't she have conferred? couldn't we have conferred? couldn't you have conferred? couldn't they have conferred?
V-ing perfect
couldn't I have been conferring? couldn't you have been conferring? couldn't she have been conferring? couldn't we have been conferring? couldn't you have been conferring? couldn't they have been conferring?