If you had followed my advice,you would be able to finish the work now.如果你当时听了我的话,现在就能完成这份工作了。(从句说明过去,主句说明现在。)
If I were you,I would have gone to her birthday party.如果我是你,我就去参加她的生日晚会了。(从句说明现在,主句说明过去。)
If you hadn't lent me some money,I couldn't have bought the new house and most likely I would be still living in the dangerous house now.假若你不借钱给我,我不可能买下这幢新房,很可能现在还住在危房里。(从句说明过去,主句说明过去和现在。)