Question

Not until I began to work ________ how much time I had wasted.

1. A.
   didn't I realize
2. B.
   did I realize
3. C.
   I didn't realize
4. D.
   I realize

Answer 1

B
這是一個倒裝句型。帶有否定意義的詞或短語放在句首，語序需要部分倒裝。常見的詞語有not，never，seldom，scarcely，barely，little，at no time，not only，not once，under，no condition，hardly…when，no sooner…than等。這里not until是否定副詞，因此選B。