The main language of Libya is Arabic, which is spoken across the country with some variations in the dialect. The western part of the country speaks a dialect more similar to that of Tunisia and the other North African Arab countries, such as Algeria. In the eastern part of Libya where you can find the city of Benghazi, they speak a dialect that is more similar to Egyptian Arabic.
Libya also has a sizeable Berber population that speak local Berber languages, sometimes these are referred to as Amazigh or Tamazight. Berber languages are indigenous to North Africa and are spoken by millions in the region. Most of the speakers today can be found in Morocco and Algeria with some also spread through Libya, Tunisia, Mali, Niger and Mauritania.
Berber languages share many borrowed words from Arabic, however the languages are not mutually intelligible. But to the untrained ear who understands a few things in Arabic, they might sound similar. There is currently an estimated 300,000 Berber speakers in Libya still today.