الملخص
Case marking is a linguistic system through which inflectional marks or endings are added to lexical items like nouns or adjectives. It is widely known that languages differ in this regard. Case marking is overt in many languages, such as Standard Arabic (SA), Latin, German, and Russian. It is employed in such languages to distinguish between syntactic categories, particularly nominal arguments in terms of their grammatical relations (i.e., subjects and objects). Such languages also have a more flexible word order compared with languages that do not have the system of overt case marking, like English and French. A relation of cause and effect has been established here between case marking and the flexibility of word order. Nevertheless, certain varieties of Arabic, such as Najdi Arabic (NA), have a flexible word order too, even though they lack case markings which triggers the main research question of this paper. The paper aims to check whether case marking is really the linguistic factor behind the flexibility of word order in Arabic. To answer this question, the paper compares and contrasts the role of case marking to the role of semantic properties in identifying the grammatical relations of arguments. It also refers to ‘agreement’ and other relevant linguistic factors. The paper also explores the word order in NA and compares it to that of SA. In addition to presenting and describing fairly sufficient data from these two languages, the paper includes a theoretical analysis of the data within the framework of Head-driven Phrase Structure Grammar (HPSG) and Linking Theory. The conclusion reached in this paper is that case marking may play a role in determining the word order in SA, but attributing the flexibility of word order in Arabic to case marking is possibly a misleading claim.