"ever since" 是一个 介词短语，用于表示某个事件或时间点之后一直持续到现在的情况或状态。它通常跟在句首，后面常跟一般过去时，表示某个动作或状态从过去一直持续到现在。例如：

1. Ever since she moved to the city, she has been working on her art.

2. Ever since the accident, he has been unable to walk.

3. Ever since I was a child, I have loved reading books.

在这个结构中，"ever since" 作为时间状语，后面跟着的从句通常使用一般过去时，以强调从过去某个时间点开始一直持续到现在的动作或状态。