I could blunder you could blunder he could blunder we could blunder you could blunder they could blunder
V-ing form
I could be blundering you could be blundering he could be blundering we could be blundering you could be blundering they could be blundering
Perfect
I could have blundered you could have blundered he could have blundered we could have blundered you could have blundered they could have blundered
V-ing perfect
I could have been blundering you could have been blundering he could have been blundering we could have been blundering you could have been blundering they could have been blundering
Negation
Simple form
I could not blunder you could not blunder he could not blunder we could not blunder you could not blunder they could not blunder
V-ing form
I could not be blundering you could not be blundering he could not be blundering we could not be blundering you could not be blundering they could not be blundering
Perfect
I could not have blundered you could not have blundered he could not have blundered we could not have blundered you could not have blundered they could not have blundered
V-ing perfect
I could not have been blundering you could not have been blundering he could not have been blundering we could not have been blundering you could not have been blundering they could not have been blundering
Interrogative form
Simple form
could I blunder? could you blunder? could he blunder? could we blunder? could you blunder? could they blunder?
V-ing form
could I be blundering? could you be blundering? could he be blundering? could we be blundering? could you be blundering? could they be blundering?
Perfect
could I have blundered? could you have blundered? could he have blundered? could we have blundered? could you have blundered? could they have blundered?
V-ing perfect
could I have been blundering? could you have been blundering? could he have been blundering? could we have been blundering? could you have been blundering? could they have been blundering?
Interro-negative form
Simple form
could I not blunder? could you not blunder? could he not blunder? could we not blunder? could you not blunder? could they not blunder?
V-ing form
could I not be blundering? could you not be blundering? could he not be blundering? could we not be blundering? could you not be blundering? could they not be blundering?
Perfect
could I not have blundered? could you not have blundered? could he not have blundered? could we not have blundered? could you not have blundered? could they not have blundered?
V-ing perfect
could I not have been blundering? could you not have been blundering? could he not have been blundering? could we not have been blundering? could you not have been blundering? could they not have been blundering?