could i have been stringing?
could you have been stringing?
could he have been stringing?
could we have been stringing?
could they have been stringing?
could i not be stringing?
could you not be stringing?
could he not be stringing?
could we not be stringing?
could they not be stringing?
could i not have strung?
could you not have strung?
could he not have strung?
could we not have strung?
could they not have strung?
could i not have been stringing?
could you not have been stringing?
could he not have been stringing?
could we not have been stringing?
could they not have been stringing? 