Why are language names in Greek always in plural?

Question

eg: τα ελληνικά, αραβικά, κτλ.

Answer 1

In order to say “I speak English” (or any other language), we can use two different structures in Greek. We can say “Μιλάω την Αγγλική” (meaning “Μιλάω την Αγγλική γλώσσα” = I speak the English language) or “Μιλάω Αγγλικά” (meaning “Μιλάω Αγγλικά λόγια” = I speak  English words).

The second structure is much  more common nowadays, probably because it is a shorter phrase.