A. 部分否定(not + all, both, everyなど)
  1. Life is not all pain.
  2. The rich are not always happy.
  3. Not every winner gets the yellow jersey.
B. 仮定法過去…現在の事実に反する仮定を表す
  1. If Jill were [was] here, she would help us.
    cf. As she is not here, she cannot help us.
  2. If life were all pain, it would be unbearable.
  3. Supposing you could go abroad, where would you like to go first?
C. 仮定法過去完了…過去の事実に反する仮定を表す
  1. If we had not overcome many difficulties, we could not have felt great happiness.
    cf. We overcame many difficulties, so we were able to feel great happiness.
  2. If the program had not been troubled by political problems, there might have been very good cooperation.