I must refine you must refine he must refine we must refine you must refine they must refine
V-ing form
I must be refining you must be refining he must be refining we must be refining you must be refining they must be refining
Perfect
I must have refined you must have refined he must have refined we must have refined you must have refined they must have refined
V-ing perfect
I must have been refining you must have been refining he must have been refining we must have been refining you must have been refining they must have been refining
Negation
Simple form
I mustn't refine you mustn't refine he mustn't refine we mustn't refine you mustn't refine they mustn't refine
V-ing form
I mustn't be refining you mustn't be refining he mustn't be refining we mustn't be refining you mustn't be refining they mustn't be refining
Perfect
I mustn't have refined you mustn't have refined he mustn't have refined we mustn't have refined you mustn't have refined they mustn't have refined
V-ing perfect
I mustn't have been refining you mustn't have been refining he mustn't have been refining we mustn't have been refining you mustn't have been refining they mustn't have been refining
Interrogative form
Simple form
must I refine? must you refine? must he refine? must we refine? must you refine? must they refine?
V-ing form
must I be refining? must you be refining? must he be refining? must we be refining? must you be refining? must they be refining?
Perfect
must I have refined? must you have refined? must he have refined? must we have refined? must you have refined? must they have refined?
V-ing perfect
must I have been refining? must you have been refining? must he have been refining? must we have been refining? must you have been refining? must they have been refining?
Interro-negative form
Simple form
mustn't I refine? mustn't you refine? mustn't he refine? mustn't we refine? mustn't you refine? mustn't they refine?
V-ing form
mustn't I be refining? mustn't you be refining? mustn't he be refining? mustn't we be refining? mustn't you be refining? mustn't they be refining?
Perfect
mustn't I have refined? mustn't you have refined? mustn't he have refined? mustn't we have refined? mustn't you have refined? mustn't they have refined?
V-ing perfect
mustn't I have been refining? mustn't you have been refining? mustn't he have been refining? mustn't we have been refining? mustn't you have been refining? mustn't they have been refining?