"Engage in" 和 "be involved in" 都可以表示某人参与或参加某项活动或事件，但它们的用法和含义略有不同。

"Engage in" 强调主动参与或专注于某项活动或任务，通常指某人积极地参与并专注于活动或任务。例如：

She engages in daily exercise to stay healthy.

He engages in deep conversation with his colleagues to build strong relationships.

"Be involved in" 则强调某人在某项活动或事件中扮演了一个角色或被卷入其中。它可以指积极参与，也可以指不自愿地被卷入其中。例如：

She was involved in a car accident yesterday.

He is involved in various charity organizations and always volunteers to help out.

因此，两个短语的区别在于 "engage in" 更强调主动的参与和专注，而 "be involved in" 更强调角色或被动参与。