You should collect persuasive language samples—we’ll convince you.

We’ve talked before about language sampling with older students, and how using narrative or expository (informational) tasks are better than conversation at aligning with academic expectations and eliciting complex syntax. But what about persuasive language? It’s important for school, sure, but also students’ personal interactions. For every time they need to lay out an argument in an essay or debate, they’ll have dozens of opportunities to convince a friend, parent, teacher, or someone else to see things their way. Talking a classmate out of risky behavior, explaining a situation to a cop… it doesn’t take too much imagination to see the potential importance of this skill. And when you’re speaking (or writing) persuasively, you have to convey complex ideas in a concise and clear way, requiring especially deft use of complex syntax.


The authors of this paper found that ninth-graders responding to a persuasive prompt (giving reasons why teens should or should not have jobs) used more complex syntax than in response to an expository one (explaining how a teacher can be a role model to teens). They also compared different modalities—written responses to expository prompts were more complex than spoken ones, but the results were mixed with persuasive samples. The researchers measured complexity (and you can too!) by the percentage of complex sentences and the average number of clauses per sentence. There were some specific differences in microstructure—types of verbs and clauses, for examples—between the two genres as well, that the paper lays out in more detail.  

So keep this in mind when you’re next assessing an older student: allowing a written response for an expository language sample will elicit more complex language, but with a persuasive prompt, you can go either way and maximize that complex syntax.


Brimo, D., & Hall-Mills, S. (2018) Adolescents’ production of complex syntax in spoken and written expository and persuasive genres. Clinical Linguistics & Phonetics. Advance online publication. doi: 10.1080/02699206.2018.1504987