Expository discourse, or “informational language”, as suggested by the name, is language used to explain, inform and describe (Ukrainetz, 2024). Also known as “the language of the curriculum”, it is the academic language used in class lectures and textbooks, and required in student presentations, essays and reports. It’s also used when explaining how to bake a cake, in a textbook explanation of photosynthesis, or in an essay describing the causes and consequences of a historical event.
There are different varieties of exposition, such as description, enumeration, causation, and comparing and contrasting; each has its own particular organizational structure and distinguishing features. What connects these disparate activities is an intent to convey factual or technical information in an abstract, generalized way (Ukrainetz, 2024).
Whilst conversation and narrative discourse tend to be more personal and social in nature, often referring to specific people and events, informational language tends to relate to more general concepts and processes. Although specific events or experiences may be mentioned, they are typically transcended to focus on “what generally happens”. This is reflected in the use of the present and infinitive tenses, compared to the narrative past tense (Ukrainetz, 2024).
Whilst narrative discourse predominates at primary school, and continues to develop at secondary school, expository discourse comes to the fore. Although less familiar, it is central to teaching and learning at the secondary level, and students are expected to spend a large part of their day reading and listening to expository discourse (Scott, 2009).
Worryingly, expository discourse is also one of the hardest genres to understand (Nippold, 2017). In one study, primary school children were found to have consistently poorer understanding of expository texts than narratives (Snyder and Caccamise, 2008). Correspondingly, Cheryl Scott (2009) notes that informational sentences written by adults tended to be longer and more complex than narrative sentences.
In another landmark study, Marilyn Nippold and colleagues recruited 120 typically developing individuals from ages 7 to 49 in order to compare conversational and expository speech samples across different ages. The conversational samples were based on common subjects such as participants’ friends, families, school, or work. For the expository sample, they asked participants to explain the rules of their favourite game or sport (Nippold et al, 2005).
The results revealed greater syntactic complexity for the expository samples compared to the conversational samples across all age groups. Nippold argued that the increased cognitive demands of the expository task had compelled the subjects to use more advanced sentence structures (Nippold et al, 2005). In a later article, she asserted that “complex thought encourages complex talk” (Nippold, 2014).
So what exactly makes expository discourse more complex, and harder to understand? In a general sense, since its object is to convey new information, exposition is inherently more challenging (Nippold, 2017). More specifically, there are numerous lexical, grammatical and structural features that distinguish expository text and make it more challenging for the average person, let alone those with language disorders.
Firstly, expository texts have a higher proportion of content words (nouns, adjectives and verbs) than narratives or conversational discourse (Balthazar et al, 2010). Compared to the small, familiar lexicon of casual conversation, exposition is distinguished by a richer, more varied vocabulary through which to convey its various concepts. Words tend to be more precise, abstract and technical, as well as multisyllabic and often morphologically complex. According to Beck’s three tier hierarchy, advanced Tier 2 words as well as low-frequency and specialized Tier 3 words are more commonly found (Beck et al, 2013; Ukrainetz, 2024).
Informational sentences also tend to be longer and more complex, involving multiple subordinate clauses structured in a hierarchical rather than linear fashion so as to highlight the most important information (Balthazar et al, 2010). Specific grammatical features of exposition that may be particularly difficult to understand include nominalization and pre- and post-modification of the noun phrase (Ukrainetz, 2024).
Nominalisation is the process of turning a verb into a noun, and is commonly used in both science and history, e.g. “evaporation” (from evaporate), “neutralization” (from neutralize) and “colonisation” (from colonise). It is useful for writers since it allows them to pack more information into a sentence, but harder for readers because it hides the agent and action, making sentences feel denser and more abstract.
Pre- and post-modification refers to adding words before or after a noun to add detail, creating a noun phrase. Again, it is commonly used in science and can serve a useful function as a way of teaching new vocabulary (Balthazar et al, 2010), e.g. “Chlorophyll, a pigment that causes plants to be green, is vital for photosynthesis”, and “the microscopic capillaries connecting the smallest arteries to the smallest veins”.
In the first sentence, the noun “chlorophyll” is modified by following it with the appositive, “a pigment that causes plants to be green”, creating a noun phrase with a definition embedded. In the second instance, the pre-modifier “microscopic” and the following participial phrase, “connecting the smallest arteries…” give clues to the meaning of the word “capillary” in terms of size and location.
These structures provide a useful way of teaching new information without using too many words. However, a student with poor syntactic knowledge would struggle to decipher sentences such as these and might miss out on the explanations. (For a more detailed look at some of the linguistic features that distinguish expository discourse, please see my post on literate language.)
As touched on briefly earlier, exposition encompasses a wide range of different subgenres, each with their own distinguishing features, and this too, makes it difficult to engage with. Whilst a student can rely on the familiar structure of a narrative, many different rules have to be learnt for exposition, and some varieties have almost no structure (Ukrainetz, 2024).
Ultimately, understanding and expression of expository discourse is a complex task requiring a rich and varied vocabulary, advanced grammatical understanding, awareness of different organisational structures and topic knowledge as well as other cognitive skills such as adequate working memory. Unfortunately, students with language disorders tend to struggle in all of these areas.
Notes
Balthazar, Catherine H., and Cheryl M. Scott. “The Grammar of Information: Challenges for Older Students with Language Impairments.” Topics in Language Disorders 30, no. 4 (2010): 313–327.
Nippold, Marilyn. (2014). Language Intervention at the Middle School: Complex Talk Reflects Complex Thought. Language, Speech, and Hearing Services in Schools. 45. 153-156. 10.1044/2014_LSHSS-14-0027.
Nippold, Marilyn A. 2017. “Reading Comprehension Deficits in Adolescents: Addressing Underlying Language Abilities.” Language, Speech, and Hearing Services in Schools 48 (2): 125–131.
Nippold, Marilyn A., Linda J. Hesketh, Jill K. Duthie, and Tracy C. Mansfield. “Conversational versus Expository Discourse: A Study of Syntactic Development in Children, Adolescents, and Adults.” Journal of Speech, Language, and Hearing Research 48, no. 5 (October 2005): 1048–64.
Scott, Cheryl M. “A Case for the Sentence in Reading Comprehension.” Language, Speech, and Hearing Services in Schools 40, no. 2 (2009): 184-191.
Snyder, Lynn, and Donna Caccamise. 2008. “Comprehension Processes for Expository Text: Building Meaning and Making Sense.” In New Directions in Communication Disorders Research: Integrative Approaches, edited by M. A. Nippold and C. M. Scott, 13–39. New York: Psychology Press.
Ukrainetz, Teresa A. “Evidence-Based Expository Intervention: A Tutorial for Speech-Language Pathologists.” American Journal of Speech-Language Pathology 33, no. 2 (2024): 654–675.
Thoughts of a secondary school SLT 