I am just wrapping up another semester supervising graduate students at BU's Academic Speech, Language and Hearing Clinic. In gaining baseline and post-treatment data, I am always steering them to look through the Narrative level at microstructure aspects (e.g. complex sentences). For several semesters, we've been using the excellent resources at Columbia University's Leaders Project and their School Aged Language Assessment (SLAM) cards. These are easy to use and provide a criterion-referenced measure as well as a good simple language sample. Digitally, these are also all available for free at Boom Learning (search for Leader's Project). I recently noted some versions for preschool students including stories for prediction, and look forward to trying these out. 

I am not sure why I am finding this image amusing. That's just me, I guess.

I did a recent assessment also where I incorporated the CUBED, which provides free language assessment measures including narrative-- these are from the team who created the Story Champs® program. CUBED materials have been created for PK-Grade 3 and consist of a paragraph-level verbally presented story and range of assessment activities (e.g. retell, vocabulary description, and personal narrative prompt). The forms of the CUBED make it simple to provide a view of story grammar and complex sentence formulation.