If you ride a bicycle every day, you will have saved a lot of money by the end of the month.

will 是助动词，表示"将要"，用于构成将来时态。 have 是助动词，与过去分词 saved 构成完成时态，表示"已经"。 will have saved 是将来完成时态，表示到将来某个时间点（月底）时已经完成的动作（省钱）。