What Teachers Need to Know about Sentence Comprehension

Awhile back, I posted an opinion piece calling for the explicit teaching of sentence comprehension. With schools aiming to expose kids to complex text, it would seem that such instruction would be de rigueur. Texts are often complex because they include complicated sentences and experience tells me that students often fail to grasp the meaning of individual sentences — undermining their ability to identify main ideas, make inferences, draw conclusions, or answer any of the other question types.  

Given that comprehension lessons tend to focus on “prior knowledge,” vocabulary, text reading with follow-up questions, comprehension strategies, the lowly sentence gets short shrift in most programs and classrooms.

In any event, while that rant gathered some attention, it came up short.  

Accordingly, I have decided to take a mulligan.

That blog articulated my opinions but neither marshalled the research evidence, nor provided much in the way of helpful instructional guidance. It called for action but was terse on specifics.

This piece should remedy those omissions.

To tell the truth, when I wrote that blog I didn’t bother to search for research on sentence comprehension because, that topic never attracted much attention. There were some old studies indicating that teaching formal grammar had no impact on comprehension or writing. That seemed to settle it for most of us.

When I was working on my doctorate, a prominent reading scholar told me that “Noam Chomsky is dead.” He meant it figuratively as he was trying to dissuade me from squandering my time on something as pointless as sentence comprehension.

No matter my excuses, boy was that a foolish oversight!

Over the past two decades — slowly, gradually — research on syntax and reading comprehension has accumulated. And, over the past couple of years, the numerous publications appearing in high quality psychological, educational, and linguistic journals suggests that being a sentence comprehension researcher is now a respectable line of work, along with social media consultant or TikTok dancer.

First, the research.

These days we’re all doing some handwringing over supply lines. Nevertheless, there are clearly no supply line problems to report when it comes to sentence-comprehension studies. The desert has become an oasis. 

There is now a slew of rigorous studies revealing that an understanding of syntax is correlated with reading comprehension (Rand, 2002). That simply means that students who know more about how sentences are constructed do better on reading comprehension measures.

Even more persuasive is that many such studies examined that relationship AFTER controlling for differences in decoding ability, vocabulary knowledge, memory, and/or other relevant reading skills (Bowey, 1986; Bowey & Patel, 1988; Brimo, Apel, & Fountain, 2017; Brimo, Lund, & Sapp, 2018; Cain, 2007; Catts, Adlof, & Weismer, 2006; Cutting & Scarborough, 2006; Deacon & Kieffer, 2018; Gaux & Gombert, 1999; Farnia & Geva, 2013; Goodwin, Petscher, & Reynolds, 2022; Gottardo, Mirza, Koh, Ferreira, & Javier, 2018; Hagtvet, 2003; Mackay, Lynch, Duncan, & Deacon, 2021; Mokhtri & Thompson, 2006; Nation & Snowling, 2000; Nippold, 2017; Nomvete & Easterbrooks, 2019; Poulsen, Nielsen, & Vang Chrisensen, 2022; Scarborough, 1990; Scott, 2015; Shiotsu & Weir, 2007; Sorenson Duncan, Mimeau, Crowell, & Deacon, 2021; Tong & McBride, 2015).

In other words, if all students did equally well on decoding, vocabulary, and memory tests, we’d still see variations in reading comprehension ability because of syntax difference. The kids who understand syntax comprehend better than the ones who don’t.

That list of studies is impressive, but not comprehensive. I didn’t search carefully for these studies — combing through reference lists, using a variety of search terms and strategies, considering books and doctoral dissertations, and so on.

It is fair to point out that some such studies didn’t find significant relationships between syntax and comprehension (e.g., Cain & Oakhill, 2006), though the data are sufficiently one-sided enough to conclude that any honest meta-analysis would conclude that knowledge of syntax is an essential reading skill.

That collection of studies cited above found sentence knowledge to be important to comprehension as early as 30-months old and throughout the school grades, K-12. They found that syntax mattered with regular classroom kids and those with dyslexia. They reported this pattern in English, French, Dutch, and Cantonese. They found syntax to matter with native English speakers and with English Language Learners. Syntax played a significant role in comprehension both in studies that measured those simultaneously, and in longitudinal studies which considered the role of the relationship in learning and development.

The amount of comprehension variance explained by syntax varied quite a bit from study to study (~5% to 30%). Researchers attributed some of those differences to the nature of the syntax measures, suggesting that the ability to make sense of complex sentences is more crucial than the ability to evaluate grammatical accuracy (e.g., Brimo, Lund, & Sapp, 2018). Researchers paid less attention to variations in reading comprehension measurement.

The texts included in comprehension tests can vary a great deal in sentence complexity, and in whether the questions they ask tap into this complexity (Shanahan & Kamil, 1984).

This concern is important since syntax is a particularly important factor determining text complexity or comprehensibility (Graisser, McNamara, & Kulikowich, 2011; Stenner & Swartz, 2012). Texts with more complicated sentence structures will be a special challenge for kids who lag in sentence comprehension ability. However, at least for fifth-graders the ability to make sense of sentences with simple structures was more closely related to reading comprehension than doing so with more difficult sentences; though this may have been due to the specific demands of the particular comprehension measure used in the study (Sorenson Duncan, Mimeau, Crowell, & Deacon, 2021).

Another relevant collection of studies is those focused on oral reading fluency or text reading fluency. Such research has long shown that oral sentence reading requires skills beyond those required to read word lists – even when the words in the lists and sentences are identical (Jenkins, Fuchs, van den Broek, Espin, & Deno, 2003). That study found sentence reading to be more predictive of reading comprehension than was word list reading. Students with specific reading comprehension deficits read word lists as well as comparison students but perform more poorly than controls on text reading fluency (Cutting, Matterek, Cole, Levine, & Mahone, 2009). Research also has reported that syntax and text prosody are related to each other and to reading comprehension (Veenendaal, Groen, & Vehoeven, 2015).

If that provocative but incomplete review of the research isn’t enough to convince you that sentence comprehension is a thing, then you likely can’t be convinced. Your lifetime membership in the Flat Earth Society is safe and secure for the time being.

For those of you who are more open minded, let’s turn to what we know about teaching sentence comprehension.

I’d love to present an equally impressive array of studies showing that if you teach sentences your state test scores will reach levels just this side of Nirvana. Unfortunately, I can’t do that.

A thoughtful review (MacKay, Lynch, Duncan, & Deacon, 2021; Stoddard, Valcante, Sindelar, O’Shea, & Algozzine, 1993) recently concluded that this research is so severely limited and insufficient that it would be unwise yet to proceed pedagogically. The reasoning of these researchers is admirable and consistent with what I usually espouse – don’t try to apply basic research to classroom practice. Wait for the instructional studies!

MacKay and company rightly point out that some interventions aimed at improving sentence comprehension haven’t worked (e.g., Balthazar & Scott, 2018), and that interventions aimed at sentence comprehension have been hopelessly confounded (e.g., Morris, et al., 2012; Proctor, Silverman, Harring, Jones, & Hartranft, 2000; Reynolds, 2021). Although these studies reported significant reading comprehension improvement, they didn’t focus on syntactic work alone but also taught morphology, vocabulary, or text structure; perhaps the gains were due to one or another of them.

The same point could be made about paraphrasing studies (Stevens, Vaughn, House, & Stillman-Spisak, 2020). Although such teaching must include some attention to translating sentences into one’s own words – for the most part, these studies have emphasized paragraph paraphrases which would likely include skills that go beyond sentence interpretation. Though this approach has been successful at improving reading comprehension, it would be inappropriate to conclude from this alone that sentence instruction is a good idea.

Despite these problems, in this case, I’m going to suggest the appropriateness of cautiously proceeding with sentence comprehension teaching.

First, I believe studies that show a close connection between text reading fluency and reading comprehension to be persuasive. (I cited a few such studies but could include many more; see Breznitz, 2005 for a more rigorous treatment of these issues). MacKay and her colleagues didn’t credit this dimension of the work, but if you do then the many studies showing that oral reading guidance and chunking instruction can improve reading comprehension need to be considered (NICHD, 2000; Stevens, 1981). They suggest that teaching students how to read sentences aloud with proper prosody is effective, and I believe those practices to be examples of effective sentence instruction.

Also, I know researchers differ in the weight they accord to sentence manipulation instruction. I tend to be persuaded that sentence combining and reduction improves reading comprehension (Neville & Searls, 1985; O’Hare, 1973; Wilkinson & Patty, 1993), and that provides another body of supportive instructional data – though I admit the quality of some of these studies is dubious, it is also fair to point out that the results were just as good in the best designed and implemented studies.

Finally, I identified a couple of studies that were beyond the purview of the MacKay review. One of these studies taught 9- and 10-year-olds to read fables and to identify complex sentences, constituent clauses, and subordinate conjunctions in those texts, and then to revise the fables to make them more readable. This results in significant gains in both oral and written language.

I also recently discovered a doctoral dissertation that evaluated the impact of an intriguing sentence comprehension intervention that improved reading achievement for high school students – grades 9 and 11 (Rozen, 2005). That study had teachers guiding students to analyze difficult texts sentence-by-sentence, discussing main ideas, author’s purpose, inferences, and styles of passage as expressed or revealed in those sentences. They also taught students to break down difficult sentences, simplifying them, and determining the primary function of the various phrases (e.g., who does what to whom?).

The comparison groups received all the business-as-usual reading instruction — including vocabulary, strategies, and practice reading of the texts. The 15-minutes per day of sentence work was accomplished by reducing the time accorded to the other skills. The classes were taught by the same teacher and control and experimental students read the same texts.

My advice to teachers?

1. Teach oral reading fluency either with grade level classroom texts, including the texts for social studies and science. In the upper grades focus specifically on prosody issues. If the students are not reading the sentences properly — attending to punctuation and pausing in the appropriate places in terms of meaning, then the sentences will make no sense. (Although I know of no research on the practice, but I wouldn’t hesitate with older students to focus this fluency work on the reading of specific complicated sentences drawn from appropriate texts).

2. I think it also makes sense to engage students in sentence combining and reduction — combining simple sentences to make complex ones and breaking more complicated sentences down into their constituent parts. For examples of this kind of work, along with a wealth of other practical syntax teaching approaches, I recommend downloading the document, Syntactic Awareness: Teaching Sentence Structure (opens in a new window) by Joan Sedita. 

3. Lots of times teachers tell me they aren’t too sure whether a sentence may seem complex to the students. A good readable source that can provide guidance for identifying sentences that may be barriers to comprehension can be found for free online; an article by Cheryl M. Scott and Catherine Balthazar, The Role of Complex Sentence Knowledge in Children with Reading and Writing Difficulties (opens in a new window), provides great advice regarding sentence length, subordination, relative clauses, passive voice, and other syntactic issues. Remember that even more basic sentences may pose challenges for elementary students. However, no matter how complex a sentence may be, it is only worth breaking down if it poses some impediment to comprehension. Scott and Balthazar’s guidance may help you to notice whether a sentence poses a particular kind of problem (like a passive sentence seemingly confusing actor and acted upon), but an exercise aimed at comprehending such a structure, should start with a question to determine whether or not students could understand it. If understood, move on. If not understood, it would be a great basis for a lesson.

4. I think that idea of replacing some typical “guided reading” with the kind of reading intervention described earlier — guiding students to read each sentence, to paraphrase what they mean, and to break the sentences down when they have trouble paraphrasing. That strikes me as a very intelligent and supportive way to teach these skills — going faster when the kids are having no problem with a sentence and digging in to solve the problem when they do. 

5.  Although I’ve emphasized sentences heavily here, it is important to remember that individual words play an important role in sentence interpretation and syntactic understanding (Adlof & Catts, 2015; Goodwin, Petscher, & Reynolds, 2022). Meaning will often turn on coordinating conjunctions (e.g., and, but, so) or subordinating conjunctions (e.g., because, when, if). Likewise, verb tenses (e.g., swim and swam) reveal when actions took place or are taking place or will take place in time. Sentence work requires some attention to word meanings and morphology.

6. There have been several successful reading interventions that included sentence work. Those studies aren’t sufficient to determine the effectiveness of the sentence comprehension part of the instruction. Nevertheless, we can take some direction from such studies — including sentence work while still teaching vocabulary, morphology, text structure, and so on. These days vocabulary instruction seems to be getting a lot of play, though the contribution of syntax to reading comprehension is similar in magnitude (Deacon & Kieffer, 2018; Shiotsu & Weir, 2007). Perhaps 15 minutes per day on sentence comprehension would be a good use of reading instruction time.