L-Parameter: Morphological case marking

From Contribution: Sinitic between Altaic and Mainland Southeast Asia

This refers to the use of suffixes to mark grammatical case, such as accusative, datives, or ablative. This is a highly atypical feature for Sinitic, found only in the "Amdo-Mandarin" varieties in the northwest, resulting from intense contact with case-rich Altaic and Tibetic languages.