I could advance you could advance she could advance we could advance you could advance they could advance
V-ing form
I could be advancing you could be advancing she could be advancing we could be advancing you could be advancing they could be advancing
Perfect
I could have advanced you could have advanced she could have advanced we could have advanced you could have advanced they could have advanced
V-ing perfect
I could have been advancing you could have been advancing she could have been advancing we could have been advancing you could have been advancing they could have been advancing
Negation
Simple form
I could not advance you could not advance she could not advance we could not advance you could not advance they could not advance
V-ing form
I could not be advancing you could not be advancing she could not be advancing we could not be advancing you could not be advancing they could not be advancing
Perfect
I could not have advanced you could not have advanced she could not have advanced we could not have advanced you could not have advanced they could not have advanced
V-ing perfect
I could not have been advancing you could not have been advancing she could not have been advancing we could not have been advancing you could not have been advancing they could not have been advancing
Interrogative form
Simple form
could I advance? could you advance? could she advance? could we advance? could you advance? could they advance?
V-ing form
could I be advancing? could you be advancing? could she be advancing? could we be advancing? could you be advancing? could they be advancing?
Perfect
could I have advanced? could you have advanced? could she have advanced? could we have advanced? could you have advanced? could they have advanced?
V-ing perfect
could I have been advancing? could you have been advancing? could she have been advancing? could we have been advancing? could you have been advancing? could they have been advancing?
Interro-negative form
Simple form
could I not advance? could you not advance? could she not advance? could we not advance? could you not advance? could they not advance?
V-ing form
could I not be advancing? could you not be advancing? could she not be advancing? could we not be advancing? could you not be advancing? could they not be advancing?
Perfect
could I not have advanced? could you not have advanced? could she not have advanced? could we not have advanced? could you not have advanced? could they not have advanced?
V-ing perfect
could I not have been advancing? could you not have been advancing? could she not have been advancing? could we not have been advancing? could you not have been advancing? could they not have been advancing?