I could decalcify you could decalcify she could decalcify we could decalcify you could decalcify they could decalcify
V-ing form
I could be decalcifying you could be decalcifying she could be decalcifying we could be decalcifying you could be decalcifying they could be decalcifying
Perfect
I could have decalcified you could have decalcified she could have decalcified we could have decalcified you could have decalcified they could have decalcified
V-ing perfect
I could have been decalcifying you could have been decalcifying she could have been decalcifying we could have been decalcifying you could have been decalcifying they could have been decalcifying
Negation
Simple form
I could not decalcify you could not decalcify she could not decalcify we could not decalcify you could not decalcify they could not decalcify
V-ing form
I could not be decalcifying you could not be decalcifying she could not be decalcifying we could not be decalcifying you could not be decalcifying they could not be decalcifying
Perfect
I could not have decalcified you could not have decalcified she could not have decalcified we could not have decalcified you could not have decalcified they could not have decalcified
V-ing perfect
I could not have been decalcifying you could not have been decalcifying she could not have been decalcifying we could not have been decalcifying you could not have been decalcifying they could not have been decalcifying
Interrogative form
Simple form
could I decalcify? could you decalcify? could she decalcify? could we decalcify? could you decalcify? could they decalcify?
V-ing form
could I be decalcifying? could you be decalcifying? could she be decalcifying? could we be decalcifying? could you be decalcifying? could they be decalcifying?
Perfect
could I have decalcified? could you have decalcified? could she have decalcified? could we have decalcified? could you have decalcified? could they have decalcified?
V-ing perfect
could I have been decalcifying? could you have been decalcifying? could she have been decalcifying? could we have been decalcifying? could you have been decalcifying? could they have been decalcifying?
Interro-negative form
Simple form
could I not decalcify? could you not decalcify? could she not decalcify? could we not decalcify? could you not decalcify? could they not decalcify?
V-ing form
could I not be decalcifying? could you not be decalcifying? could she not be decalcifying? could we not be decalcifying? could you not be decalcifying? could they not be decalcifying?
Perfect
could I not have decalcified? could you not have decalcified? could she not have decalcified? could we not have decalcified? could you not have decalcified? could they not have decalcified?
V-ing perfect
could I not have been decalcifying? could you not have been decalcifying? could she not have been decalcifying? could we not have been decalcifying? could you not have been decalcifying? could they not have been decalcifying?