I could skip you could skip she could skip we could skip you could skip they could skip
V-ing form
I could be skipping you could be skipping she could be skipping we could be skipping you could be skipping they could be skipping
Perfect
I could have skipped you could have skipped she could have skipped we could have skipped you could have skipped they could have skipped
V-ing perfect
I could have been skipping you could have been skipping she could have been skipping we could have been skipping you could have been skipping they could have been skipping
Negation
Simple form
I could not skip you could not skip she could not skip we could not skip you could not skip they could not skip
V-ing form
I could not be skipping you could not be skipping she could not be skipping we could not be skipping you could not be skipping they could not be skipping
Perfect
I could not have skipped you could not have skipped she could not have skipped we could not have skipped you could not have skipped they could not have skipped
V-ing perfect
I could not have been skipping you could not have been skipping she could not have been skipping we could not have been skipping you could not have been skipping they could not have been skipping
Interrogative form
Simple form
could I skip? could you skip? could she skip? could we skip? could you skip? could they skip?
V-ing form
could I be skipping? could you be skipping? could she be skipping? could we be skipping? could you be skipping? could they be skipping?
Perfect
could I have skipped? could you have skipped? could she have skipped? could we have skipped? could you have skipped? could they have skipped?
V-ing perfect
could I have been skipping? could you have been skipping? could she have been skipping? could we have been skipping? could you have been skipping? could they have been skipping?
Interro-negative form
Simple form
could I not skip? could you not skip? could she not skip? could we not skip? could you not skip? could they not skip?
V-ing form
could I not be skipping? could you not be skipping? could she not be skipping? could we not be skipping? could you not be skipping? could they not be skipping?
Perfect
could I not have skipped? could you not have skipped? could she not have skipped? could we not have skipped? could you not have skipped? could they not have skipped?
V-ing perfect
could I not have been skipping? could you not have been skipping? could she not have been skipping? could we not have been skipping? could you not have been skipping? could they not have been skipping?