This is the 5070th most frequent Polish word.
prawdziwi
"Real" or "true" (plural form).
The word 'prawdziwi' is used to describe the subjects 'przyjaciele', emphasizing their authenticity and genuineness.
Prawdziwi przyjaciele zawsze są przy Tobie.
Real friends are always by your side.
Here, 'prawdziwych' is the accusative plural form, modifying 'bohaterów', highlighting their real and noble characteristics.
W trudnych czasach poznajesz prawdziwych bohaterów.
In difficult times, you get to know genuine heroes.
In this sentence, 'prawdziwi' is attributing the quality of genuineness to 'nauczyciele', showing it as a subject modifier in its nominative plural form.