be on at

be on at

1. To be televised at a particular time. In this usage, "be on at" is a set phrase. The movie is on at 8, so I'm going to start making the popcorn now.

2. To nag someone about something. In this usage, "at" is followed by a noun or pronoun. Ugh, my mom is on at me all the time about my grades, but I just have no interest in the classes I'm taking this semester.

See also: on

be/go/keep ˈon at somebody (to do something)

(informal, disapproving) keep criticizing somebody or telling them what to do, etc: He keeps on at her all the time about her smoking.

See also: keep, on, somebody