adjective [原级] 过去的，昔日的；刚过去的，刚结束的；完成的，结束的；（语法）过去时的
I knew from past experience that alternative therapies could help. 我知道根据以前的经验其他的治疗方法可能有效。
noun [抽象名词] 过去，昔日（the past）；往事，经历；（语法）过去时，（动词的）过去式（the past）
Your past consists of all the things that you have done or that have happened to you. 经历
preposition [时间介词] 晚于，在…...之后；在…...的更远处；经过，越过；超出，超过
It was past midnight. 过了午夜。
adverb [时间副词] 从一侧到另一侧，经过；（时间）过去，逝去
Most stores have remained closed for the past three days. 在刚过去的3天里大多数商店一直关着门。
