فَهَلْ أَنْتُمْ شَاكِرُونَ
Will you, then, be thankful?
The Qurʾānic wording places the pronoun antum and the active-participle predicate shākirūn after hal. Treating it as identical to “Hal tashkurūn?” would erase a rhetorical contrast.
A verbal clause foregrounds occurrence or renewal of thanks. A nominal clause can emphasize the quality or settled disposition of gratitude. Context can also give the question an exhortative force.