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 couldn't decalcify you couldn't decalcify she couldn't decalcify we couldn't decalcify you couldn't decalcify they couldn't decalcify
V-ing form
I couldn't be decalcifying you couldn't be decalcifying she couldn't be decalcifying we couldn't be decalcifying you couldn't be decalcifying they couldn't be decalcifying
Perfect
I couldn't have decalcified you couldn't have decalcified she couldn't have decalcified we couldn't have decalcified you couldn't have decalcified they couldn't have decalcified
V-ing perfect
I couldn't have been decalcifying you couldn't have been decalcifying she couldn't have been decalcifying we couldn't have been decalcifying you couldn't have been decalcifying they couldn't 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
couldn't I decalcify? couldn't you decalcify? couldn't she decalcify? couldn't we decalcify? couldn't you decalcify? couldn't they decalcify?
V-ing form
couldn't I be decalcifying? couldn't you be decalcifying? couldn't she be decalcifying? couldn't we be decalcifying? couldn't you be decalcifying? couldn't they be decalcifying?
Perfect
couldn't I have decalcified? couldn't you have decalcified? couldn't she have decalcified? couldn't we have decalcified? couldn't you have decalcified? couldn't they have decalcified?
V-ing perfect
couldn't I have been decalcifying? couldn't you have been decalcifying? couldn't she have been decalcifying? couldn't we have been decalcifying? couldn't you have been decalcifying? couldn't they have been decalcifying?