najbliższym

In a sentence

• W najbliższym tygodniu spotkamy się w Warszawie.

  Next week, we will meet in Warsaw.

  The word 'najbliższym' is used here as an adjective in the instrumental case, describing 'tygodniu' ('week') to mean 'next' or 'upcoming'.

• Najbliższym sąsiadem naszej szkoły jest biblioteka.

  The closest neighbor to our school is the library.

  Here, 'najbliższym' functions as an adjective in the instrumental case describing 'sąsiadem' ('neighbor') to mean 'closest' or 'nearest'.

• Porozmawiamy o tym na najbliższym spotkaniu.

  We will talk about this at the next meeting.

  In this sentence, 'najbliższym' is used as an adjective in the locative case, describing 'spotkaniu' ('meeting') to indicate the upcoming meeting in terms of time.