I could clarify you could clarify she could clarify we could clarify you could clarify they could clarify
V-ing form
I could be clarifying you could be clarifying she could be clarifying we could be clarifying you could be clarifying they could be clarifying
Perfect
I could have clarified you could have clarified she could have clarified we could have clarified you could have clarified they could have clarified
V-ing perfect
I could have been clarifying you could have been clarifying she could have been clarifying we could have been clarifying you could have been clarifying they could have been clarifying
Negation
Simple form
I could not clarify you could not clarify she could not clarify we could not clarify you could not clarify they could not clarify
V-ing form
I could not be clarifying you could not be clarifying she could not be clarifying we could not be clarifying you could not be clarifying they could not be clarifying
Perfect
I could not have clarified you could not have clarified she could not have clarified we could not have clarified you could not have clarified they could not have clarified
V-ing perfect
I could not have been clarifying you could not have been clarifying she could not have been clarifying we could not have been clarifying you could not have been clarifying they could not have been clarifying
Interrogative form
Simple form
could I clarify? could you clarify? could she clarify? could we clarify? could you clarify? could they clarify?
V-ing form
could I be clarifying? could you be clarifying? could she be clarifying? could we be clarifying? could you be clarifying? could they be clarifying?
Perfect
could I have clarified? could you have clarified? could she have clarified? could we have clarified? could you have clarified? could they have clarified?
V-ing perfect
could I have been clarifying? could you have been clarifying? could she have been clarifying? could we have been clarifying? could you have been clarifying? could they have been clarifying?
Interro-negative form
Simple form
could I not clarify? could you not clarify? could she not clarify? could we not clarify? could you not clarify? could they not clarify?
V-ing form
could I not be clarifying? could you not be clarifying? could she not be clarifying? could we not be clarifying? could you not be clarifying? could they not be clarifying?
Perfect
could I not have clarified? could you not have clarified? could she not have clarified? could we not have clarified? could you not have clarified? could they not have clarified?
V-ing perfect
could I not have been clarifying? could you not have been clarifying? could she not have been clarifying? could we not have been clarifying? could you not have been clarifying? could they not have been clarifying?