I could purge you could purge he could purge we could purge you could purge they could purge
V-ing form
I could be purging you could be purging he could be purging we could be purging you could be purging they could be purging
Perfect
I could have purged you could have purged he could have purged we could have purged you could have purged they could have purged
V-ing perfect
I could have been purging you could have been purging he could have been purging we could have been purging you could have been purging they could have been purging
Negation
Simple form
I could not purge you could not purge he could not purge we could not purge you could not purge they could not purge
V-ing form
I could not be purging you could not be purging he could not be purging we could not be purging you could not be purging they could not be purging
Perfect
I could not have purged you could not have purged he could not have purged we could not have purged you could not have purged they could not have purged
V-ing perfect
I could not have been purging you could not have been purging he could not have been purging we could not have been purging you could not have been purging they could not have been purging
Interrogative form
Simple form
could I purge? could you purge? could he purge? could we purge? could you purge? could they purge?
V-ing form
could I be purging? could you be purging? could he be purging? could we be purging? could you be purging? could they be purging?
Perfect
could I have purged? could you have purged? could he have purged? could we have purged? could you have purged? could they have purged?
V-ing perfect
could I have been purging? could you have been purging? could he have been purging? could we have been purging? could you have been purging? could they have been purging?
Interro-negative form
Simple form
could I not purge? could you not purge? could he not purge? could we not purge? could you not purge? could they not purge?
V-ing form
could I not be purging? could you not be purging? could he not be purging? could we not be purging? could you not be purging? could they not be purging?
Perfect
could I not have purged? could you not have purged? could he not have purged? could we not have purged? could you not have purged? could they not have purged?
V-ing perfect
could I not have been purging? could you not have been purging? could he not have been purging? could we not have been purging? could you not have been purging? could they not have been purging?