почетком

In a sentence

• Почетком године смо почели нови пројекат.

  At the beginning of the year, we started a new project.

  Here, 'почетком' is used as an adverbial phrase indicating the time when the action took place, referring to the start of the year.

• Позвали су нас у посету почетком следеће недеље.

  We were invited to visit at the beginning of next week.

  In this case, 'почетком' functions similarly, pinpointing a specific time at the start of the referenced period (next week).

• Извештај ћемо завршити почетком марта.

  We will finish the report at the beginning of March.

  Here, 'почетком' locates the action within the initial phases of the month indicated (March).