Linguistic Components, Levels, and Modalities

One system is to categorize language according a typology of linguistic knowledge—phonology (sound knowledge), semantics (word and word relations), syntax (grammar), and pragmatics (function and use). Another system is to speak of the level of language—word, sentence, or discourse/text. Some overlap between components and levels is evident; for example, syntax plays out at the sentence level. Semantics, however, is seen at multiple levels including: word meaning (the lexicon), sentence meaning (propositions conveyed by a simple sentences and meaning relationships between clauses in complex sentences), and text meaning (organization of a text, and overall gist or core meaning, as conveyed by a succinct summary). Children and adolescents with language impairments can show various patterns of strengths and weaknesses across these levels. Acommon area of difficulty is at the sentence level—producing and understanding complex sentences that involve main and subordinate clauses characteristic of higher level language (Scott, 2009a; Silliman & Scott, 2009).

Children with sentence-level problems might post scores within normal limits on word-level (vocabulary) tests and could also show reasonable abilities in conveying an organized narrative. Sometimes the amount of contextualization in a task impacts performance at any one level. For example, a child could do poorly on a decontextualized sentence task but produce longer, complex sentences when the task is under his/her control, as when generating a story. Language tasks at the text level can either help or hurt language performance. Some children show improved performance on reading comprehension tasks when the broader context of the text or background knowledge boosts comprehension,but falter when filling in a missing word in a sentence or short text on a different type of comprehension task. Conversely, a child could perform within normal limits on sentence-level tasks or tests, but find the prospect of organizing a text, particularly an informational text, totally beyond his or her capability (Nippold & Scott, 2010). At any one level, modality (whether spoken or written language is required) can also impact performance. In this scenario, the usual pattern would be that a child might perform better in oral tasks compared with written tasks, but again, the opposite can occur, as it did in the case discussed later in this article. For this child, reading comprehension was superior to listening comprehension; this child seemed to benefit from having a permanent visual representation of information rather than the fleeting input of auditory-only stimuli.