
Megan H. answered 12/09/19
Professional English Grammar Teacher with 10 Years of Experience
While I'm not quite sure what you mean by 'proposed oder of grammatical difficulty', I hope I can help you out a bit. Arabic is among the languages which commonly gets tested in terms of the CEFR scale (the Common European Framework Reference), which was created as an efficient method for speakers of multiple languages to quickly and easily express their proficiency level in a variety of situations. For instance, when writing a resumé (or CV), I can easily write that I'm a C1 in German, and the company I'm applying for knows what that essentially means although nobody at the company speaks German themselves. The CEFR scale includes 6 levels of proficiency: A1 (beginner), A2 (advanced beginner), B1 (intermediate), B2 (advanced intermediate), C1 (advanced), C2 (native-level fluency).
If you mean precisely which grammatical points fall into each of those CEFR scales or how it is generally thought best to construct an Arabic-as-L2 curriculum, you may find the following paper of interest: https://www.researchgate.net/publication/328952339_CEFR-Oriented_Framework_for_Designing_Arabic_Language_Proficiency_Test_and_Curricula
This text proposes and explains (in both English and Arabic) an Arabic assessment method and curriculum design along the following lines (as stated by the authors in the abstract:
" • A description of the lexical items in each level and how they are selected and ordered; • A description of the grammatical elements, categories, classes, structures, processes and relations in each level, and the grammatical theory affecting that; • A description of the morphological elements and processes in each level; • A description of the semantic relations in each level; • A description of the phonological skills and their distributions among the various levels; • A description of which social groups in the target community and, perhaps, in the international community the learner need to be familiar with; • A Description of the principles according to which macro-and microfunctions are selected and ordered; • A description of the domains and whether some domains are more important than others and why; • A description of which language activities to be included in the test and/or curricula; and • Whether or not more/less levels/hours are needed and why. "