Lawmaker Ann Chiang Lai-wan of the pro-Beijing DAB party took her oath at the Legislative Council on Wednesday in Mandarin.
Most lawmakers took oath in Cantonese while some others used English, including Yau Wai-ching and Sixtus ‘Baggio’ Leung Chung-hang from Youngspiration, and Claudia Mo Man-ching of the Civic Party.
It is extremely rare for lawmakers to take oath in Mandarin, which is spoken in mainland China.
Both English and Chinese are official languages of Hong Kong. However, lawmakers may deliver their oath in any of the three languages.