Breakdown of Насчёт встречи я позвоню тебе вечером.
Questions & Answers about Насчёт встречи я позвоню тебе вечером.
Насчёт means about, regarding, or concerning.
So Насчёт встречи means about the meeting.
In this sentence, it introduces the topic of the phone call:
- Насчёт встречи = about the meeting
- я позвоню тебе вечером = I’ll call you in the evening
A very similar alternative is о встрече, but насчёт is especially common in everyday speech.
Because насчёт requires the genitive case.
The noun встреча is nominative singular. Its genitive singular form is встречи.
So:
- встреча = meeting
- насчёт встречи = about the meeting
This is something you simply have to learn with the preposition:
насчёт + genitive