أول

In a sentence

• كان هذا أول يوم في المدرسة.

  This was the first day of school.

  Here, "أول" is used as an adjective meaning 'first', describing the day.

• قال المعلم أولًا نحتاج إلى قراءة القواعد.

  The teacher said, 'First, we need to read the rules.'

  In this example, "أولًا" functions as an adverb meaning 'firstly' or 'first'.

• وصل إلى أول القرية قبل الغروب.

  He arrived at the beginning of the village before sunset.

  Here, "أول" is used as a noun meaning 'the beginning' or 'the forefront'.