Unbounded dependencies is one of the most complicated problems in NLP. Transformational grammar approach is somewhat complicated and it results in a vague analysis for unbounded dependencies. Applying generative grammar, we found that using phrase structure rules and some other rules like ID (immediate dominance) rules and LP (linear precedenc) rules, forming ID/LP grammar representing Arabic language could lead to a good result in handling unbounded dependencies in Arabic language structure. We have chosen interrogative structure as an example to show the technique of using slash features in representing unbounded dependencies