I may refine you may refine he may refine we may refine you may refine they may refine
V-ing form
I may be refining you may be refining he may be refining we may be refining you may be refining they may be refining
Perfect
I may have refined you may have refined he may have refined we may have refined you may have refined they may have refined
V-ing perfect
I may have been refining you may have been refining he may have been refining we may have been refining you may have been refining they may have been refining
Negation
Simple form
I may not refine you may not refine he may not refine we may not refine you may not refine they may not refine
V-ing form
I may not be refining you may not be refining he may not be refining we may not be refining you may not be refining they may not be refining
Perfect
I may not have refined you may not have refined he may not have refined we may not have refined you may not have refined they may not have refined
V-ing perfect
I may not have been refining you may not have been refining he may not have been refining we may not have been refining you may not have been refining they may not have been refining
Interrogative form
Simple form
may I refine? may you refine? may he refine? may we refine? may you refine? may they refine?
V-ing form
may I be refining? may you be refining? may he be refining? may we be refining? may you be refining? may they be refining?
Perfect
may I have refined? may you have refined? may he have refined? may we have refined? may you have refined? may they have refined?
V-ing perfect
may I have been refining? may you have been refining? may he have been refining? may we have been refining? may you have been refining? may they have been refining?
Interro-negative form
Simple form
may I not refine? may you not refine? may he not refine? may we not refine? may you not refine? may they not refine?
V-ing form
may I not be refining? may you not be refining? may he not be refining? may we not be refining? may you not be refining? may they not be refining?
Perfect
may I not have refined? may you not have refined? may he not have refined? may we not have refined? may you not have refined? may they not have refined?
V-ing perfect
may I not have been refining? may you not have been refining? may he not have been refining? may we not have been refining? may you not have been refining? may they not have been refining?