Store managers are often the last to hear complaints, and often find out only when their regular customers decide to frequent their competitors, according to a study jointly conducted by Verde Group and Wharton School.

　　分析主干：managers are the last to... and find out...

　　1.conducted 是过去分词作study 的后置定语。

　　2.不定式to hear...作后置定语，修饰the last，一般可以直接理解为 最不可能听到这些投诉的人 。

　　3.when 引导的时间状语从句修饰find out。该状语从句中，to frequent...作decide 的宾语。frequent 用作动词，表示 经常光顾 。译文：维德集团和沃顿商学院共同开展的一项研究显示，商店经理常常是最后一个听到顾客抱怨的人，而且只有当他们的老顾客开始频频光顾他们的竞争对手的时候他们才会发现顾客对他们的不满。