Saudi Arabia
The official language of Saudi Arabia is Arabic. The three main regional variants spoken by Saudis are Hejazi Arabic (about 6 million speakers), Najdi Arabic (about 8 million speakers), and Gulf Arabic (about 0.2 million speakers). Saudi Sign Language is the principal language of the deaf community. The large expatriate communities also speak their own languages, the most numerous of which are Tagalog (700,000), Rohingya (400,000), Urdu (380,000), Egyptian Arabic (300,000), and Indonesian (250,000).
Arabic
Within the non-peninsula varieties, the largest difference is between the non-Egyptian North African dialects (especially Moroccan Arabic) and the others. Moroccan Arabic in particular is hardly comprehensible to Arabic speakers east of Libya (although the converse is not true, in part due to the popularity of Egyptian films and other media).