πρώτη

In a sentence

• Αυτή είναι η πρώτη φορά που βλέπω αυτή τη θέα.

  This is the first time I see this view.

  Here, 'πρώτη' is an ordinal number referring to the occurrence of seeing the view for the first time.

• Ήταν η πρώτη που έφτασε στο σημείο.

  She was the first one to arrive at the location.

  In this case, 'πρώτη' is used as an adverbial expression to indicate ranking as 'the first one' among a sequence.

• Η πρώτη σκέψη που μου ήρθε ήταν να τηλεφωνήσω.

  The first thought that came to me was to make a call.

  Here, 'πρώτη' is used as an adjective describing 'σκέψη' (thought) as being the foremost in sequence.