Pragmatics - or Social Language Impairment

Here is a link to a nice overview of what a pragmatic (social) language impairment involves:
Pragmatic Language Skills and the Autism Spectrum

Although this article is specific to the autism spectrum, pragmatic skills are often included in assessments for language and literacy.  A student can have a pragmatic deficit that will interfere with literacy skills and their reading development. A weakness in social language skills will impact a student's ability to comprehend higher level stories and books.  It will also affect their ability to discuss and interpret with they read.  

Content reading at the high school level is full of idioms and figurative language. Obvious idioms, such as "how the cookie crumbles," are plentiful in teaching and speech language manuals.  There are many other less obvious ones, however, that we use every day and don't even consciously identify as figurative. If there is observable or a history evidence of a social language impairment, this should be assessed in addition to or as part of a language literacy evaluation.