Had it not been for the free tickets,I would not have gone to the film so often.

相当于：If it had not been for the free tickets,I would not have gone to the film so often.
或：Without the free tickets,I would not have gone to the film so often.
这是if引导的与过去事实相反的条件状语从句的省略倒装的情况.“If it had not been for the free tickets”怎么看上去这么怪.......有点看不懂翻译成：如果不是这些免费的票，我就不会这么经常地去看电影了。if引导的与过去事实相反的条件状语从句中，往往用过去完成时，主句结构是would/could/should/might + have done.