The arabic language in Qatar is known as peninsular Arabic. Peninsular Arabic are the varieties of Arabic spoken throughout the Arabian Peninsula. This includes the countries of Saudi Arabia, Yemen, Oman, United Arab Emirates, Kuwait, Bahrain, Qatar, Southern Iraq, Southern Iran and the tribes of Jordan (the native Jordanians). The modern dialects spoken in the Arabian Peninsula are closer to Classical Arabic than elsewhere. Some of the local dialects have retained many archaic features lost in other dialects, such as the conservation of nunation for indeterminate nouns. They retain most Classical syntax and vocabulary but still have some differences from Classical Arabic like the other dialects.
Source : wikipedia