English verb conjugation
CAN REFINE

Regular verb: refine - refined - refined

Affirmation

Simple form	V-ing form
I can refine you can refine he can refine we can refine you can refine they can refine	I can be refining you can be refining he can be refining we can be refining you can be refining they can be refining
Perfect	V-ing perfect
I can have refined you can have refined he can have refined we can have refined you can have refined they can have refined	I can have been refining you can have been refining he can have been refining we can have been refining you can have been refining they can have been refining

Negation

Simple form	V-ing form
I can't refine you can't refine he can't refine we can't refine you can't refine they can't refine	I can't be refining you can't be refining he can't be refining we can't be refining you can't be refining they can't be refining
Perfect	V-ing perfect
I can't have refined you can't have refined he can't have refined we can't have refined you can't have refined they can't have refined	I can't have been refining you can't have been refining he can't have been refining we can't have been refining you can't have been refining they can't have been refining

Interrogative form

Simple form	V-ing form
can I refine? can you refine? can he refine? can we refine? can you refine? can they refine?	can I be refining? can you be refining? can he be refining? can we be refining? can you be refining? can they be refining?
Perfect	V-ing perfect
can I have refined? can you have refined? can he have refined? can we have refined? can you have refined? can they have refined?	can I have been refining? can you have been refining? can he have been refining? can we have been refining? can you have been refining? can they have been refining?

Interro-negative form

Simple form	V-ing form
can't I refine? can't you refine? can't he refine? can't we refine? can't you refine? can't they refine?	can't I be refining? can't you be refining? can't he be refining? can't we be refining? can't you be refining? can't they be refining?
Perfect	V-ing perfect
can't I have refined? can't you have refined? can't he have refined? can't we have refined? can't you have refined? can't they have refined?	can't I have been refining? can't you have been refining? can't he have been refining? can't we have been refining? can't you have been refining? can't they have been refining?