A student with difficulties in reading fluency would primarily struggle with __________.

Reading fluency refers to the ability to read a text accurately, quickly, and with proper expression. When a student has difficulties in reading fluency, their primary struggle is with reading text at an appropriate speed. This aspect is crucial because fluency not only involves the pace of reading but also the ease and confidence with which a student can read aloud or silently. A lack of fluency can hinder a student's overall reading comprehension, as they may expend too much cognitive energy on decoding words instead of focusing on the meaning of the text.

In contrast, understanding the meaning of a text relates more closely to reading comprehension and how well a student can grasp and interpret information, which is not the main focus of fluency issues. The ability to spell words correctly is associated with writing and language mechanics rather than reading fluency. Writing essays involves organizing thoughts and ideas, which also targets different skills that are distinct from those needed for fluent reading. Thus, the characteristic struggle of a student facing challenges in reading fluency is indeed their ability to read text efficiently and with speed.