I could support you could support he could support we could support you could support they could support
V-ing form
I could be supporting you could be supporting he could be supporting we could be supporting you could be supporting they could be supporting
Perfect
I could have supported you could have supported he could have supported we could have supported you could have supported they could have supported
V-ing perfect
I could have been supporting you could have been supporting he could have been supporting we could have been supporting you could have been supporting they could have been supporting
Negation
Simple form
I could not support you could not support he could not support we could not support you could not support they could not support
V-ing form
I could not be supporting you could not be supporting he could not be supporting we could not be supporting you could not be supporting they could not be supporting
Perfect
I could not have supported you could not have supported he could not have supported we could not have supported you could not have supported they could not have supported
V-ing perfect
I could not have been supporting you could not have been supporting he could not have been supporting we could not have been supporting you could not have been supporting they could not have been supporting
Interrogative form
Simple form
could I support? could you support? could he support? could we support? could you support? could they support?
V-ing form
could I be supporting? could you be supporting? could he be supporting? could we be supporting? could you be supporting? could they be supporting?
Perfect
could I have supported? could you have supported? could he have supported? could we have supported? could you have supported? could they have supported?
V-ing perfect
could I have been supporting? could you have been supporting? could he have been supporting? could we have been supporting? could you have been supporting? could they have been supporting?
Interro-negative form
Simple form
could I not support? could you not support? could he not support? could we not support? could you not support? could they not support?
V-ing form
could I not be supporting? could you not be supporting? could he not be supporting? could we not be supporting? could you not be supporting? could they not be supporting?
Perfect
could I not have supported? could you not have supported? could he not have supported? could we not have supported? could you not have supported? could they not have supported?
V-ing perfect
could I not have been supporting? could you not have been supporting? could he not have been supporting? could we not have been supporting? could you not have been supporting? could they not have been supporting?