Problematics of Forming Plurals for Egyptian Students of German Language as Foreign Language

One of the major problematics that face the Egyptian students of German Language, as a foreign language, is changing the singular into plural. This difficulty is due to the big differences between both languages: Arabic and German languages, as the plural in German language has many grammatical forms with various morphological endings not even approved by consensus of the German grammarians.
Pragmatically and practically, this research tackles this topic through a group of Egyptian students of German Language as a foreign Language in Egypt. Thus, this study emerges some of these students problem’s on forming the plural through actualized given examples of many singulars and other artificial singulars included within the study.
Hence, this research attempts at answering the coming question:

To what extent can the Egyptian students perfect forming the plural German forms?
What are the most common mistakes on forming the plural in German language?
What are the criteria adopted by the students to structure the plural in German language?

The study shows the coming results:

The most difficult form of plural in German language is such one which is not different from the singular.
Such forms which have letters that have diacritics are often avoided because they are not involved in Arabic language.
There is an improvement in the level of the researched group of students in the second stage (of their artificial singulars), although the students do not understand these words, for they use an inherent analogy or comparison on forming those plurals.