Do adults with low reading comprehension also show low oral language comprehension, and does this hold across transparent and opaque writing systems?

Why listening comprehension is part of the reading story

Reading comprehension is not just about recognizing words on a page. It also draws on the same language machinery you use to understand speech—vocabulary, grammar, and the ability to follow ideas across sentences. If that oral language foundation is weak, reading can suffer even when word decoding is intact. This is why researchers looking at adults with low reading skills have started asking whether their listening comprehension is also low, rather than focusing only on their reading accuracy or speed [1].

In the German-speaking sample, the answer was yes on average: listening comprehension fell below the level expected for the group's age and schooling [1]. That matters because it suggests that for some adults, the reading difficulty is not only a decoding problem—it extends to understanding language more broadly.

Listening comprehension, not word reading, explained the reading gap

When the researchers statistically compared listening comprehension and word reading as predictors of reading comprehension, listening comprehension explained a meaningful share of the differences between individuals, while word reading did not [1]. In plain terms, the adults who understood spoken German better also tended to understand written German better, and their ability to read individual words accurately was not the deciding factor in this small group.

That does not mean word reading is irrelevant for every struggling adult. A separate study of 54 German-speaking adults with low reading comprehension found that decoding and word-reading fluency were extremely low on average, and phonological awareness—the ability to notice and manipulate speech sounds—was also weak on average [2]. But that same study found wide variation: a notable proportion of participants did not show deficits in basic reading skills, and reading accuracy was generally good even though text reading accuracy was deficient for about a quarter of the sample [2]. So low reading comprehension in adults is not one uniform profile, and the role of listening comprehension may be especially visible in those whose word-level skills are relatively spared.

Does the writing system change the answer?

The German findings come from a transparent orthography—a writing system where letters and sounds map onto each other fairly predictably. The authors explicitly contrast their result with previous studies of adults struggling to read English, an opaque orthography with many irregular spellings, where the relationship between listening comprehension and reading comprehension appears different [1]. In other words, the same question may get a different answer depending on how predictable the spelling system is.

Why might transparency matter? In a transparent system like German, a reader can often sound out a word correctly even without strong oral vocabulary, so word reading may be less of a bottleneck. That could make listening comprehension—the ability to make sense of the words once decoded—stand out more clearly as the limiting factor. In English, irregular spelling may place more weight on word-level reading, potentially changing which skill best explains reading comprehension. This is a hypothesis the German study's authors raise rather than confirm; they note that whether orthographic transparency explains the discrepancy should be tested in cross-orthography studies with larger samples [1].

Evidence from typical readers offers some indirect support for the idea that writing systems shape reading behavior, though not specifically for adults with low comprehension. A study of eye movements in English, German, and Finnish found that children's reading patterns differed by orthography—English children looked qualitatively different from German and Finnish children, and the predictability of the spelling system mattered more than its complexity [3]. By adulthood, however, reading behavior was remarkably similar across the three languages [3]. That similarity among proficient adults is a caution: orthography effects seen in children may not simply carry over to adults, and the question of whether they shape the listening–reading link in low-comprehension adults remains untested.

What we still cannot say

The direct evidence for low oral language comprehension in adults with low reading comprehension comes from a small sample—32 German-speaking young adults—so the average pattern is informative but not a precise estimate for all struggling adult readers [1]. The comparison with English is based on prior studies cited by the authors rather than a head-to-head test in the same study, and the authors themselves frame orthographic transparency as a possible explanation that needs further testing [1].

Other work on adults with reading difficulties has focused on how reading skills are structured and measured, without examining oral language comprehension or comparing writing systems [5]. And a study of Turkish children—Turkish being a transparent orthography—examined executive functions and reading fluency but did not include adults or a cross-orthography comparison [4]. So the honest answer is: yes, low reading comprehension and low listening comprehension can go together in adults, at least in German; whether that holds in opaque systems like English, and whether transparency is the reason, is a question the current evidence raises but does not settle.

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