1) When the main clause is in the past tense, we do not use a past perfect after as if / as though to show that a comparison is unreal. Instead we use a simple past in both clauses. - He looked as if / as though he knew everything, but he didn’t. (NOT She looked as if / as though she had known everything.) [ web link As if and as though] - 2) we do not use a past perfect for a past unreal comparison. - She looked as if she was rich, but she wasn’t. (NOT --- as if she had been rich. [ web link As if and as though] I think these two websites are same in their opinion. But after reading CLIFFS TOEFL I am in confusion. It has given a couple of examples as follows : - 1)Jeff looked as if he had seen a ghost. (He didn't see a ghost) 2)He looked as if he had run ten miles. (He didn't run ten miles) As we see here, past perfect has been used to show past unreal situation. - Aren't the rules contradictory? Could someone tell me which one is right? The website? or Cliffs Toefl?