Vocabulary development is often the province of English/language arts instruction. But it’s also a core part of Deaquanita Lancelin’s 9th grade science class in the Pine Bluff schools in Arkansas.
Every few days, Lancelin will spend about 15 minutes breaking down academic language with her students, determining the meaning of different word parts, and how those meanings can offer clues about the definition of the word as a whole.
Take the word “hydroelectric,” which was the focus of a recent lesson. If “hydro” references water, what might that demonstrate about this particular type of electric power?
Lancelin can see the “spark” go off when the meaning clicks for her students, she said. “Especially with kids on all different levels of reading, I think it is a great way to level the playing field and get that understanding,” she said.
These exercises in identifying and defining prefixes, suffixes, and root words are examples of morphology instruction—teaching children how to identify the meaningful units, or morphemes, within words.
Advocates of teaching morphology argue that it can help older students who still struggle to read multisyllabic words, and that it can support deeper and richer vocabulary development as reading becomes more complex and discipline-specific. Morphology instruction is also gaining popularity within the “science of reading” movement, which aims to align classroom practice with research evidence. Organizations such as the Reading League have offered resources on the practice.
Still, exactly how and when—or even if—to teach morphology are open questions, said Kathleen Rastle, a professor of cognitive psychology who studies language, literacy, and learning at the Royal Holloway University of London.
“The research literature on morphological instruction is patchy,” she said. “There’s not a great consensus on what should be taught and when it should be taught, and whether it should be taught explicitly.”
How morphological knowledge develops
Studies show that there are two ways that morphology knowledge matters in reading ability, said Michael Kieffer, an associate professor of literacy education at New York University who studies the language and literacy development of students from linguistically diverse backgrounds.
Knowing prefixes like “inter” and suffixes such as “ly” can help students recognize and decode longer, more complex words. But morphology knowledge also conveys meaning—the prefix “inter,” for example, means between—that can allow students to derive the meaning of words they don’t yet understand, Kieffer said.
When children are just starting to learn to read, most of the words that they come across are morphologically simple, said Rastle.
Teachers should be helping students break the code of written language, focusing on phonics—the correspondence between written letters and spoken sounds. At first, children apply these skills to short, easily decodable words.
Even so, students will come across common suffixes in the books that they’re reading—word endings like “ed,” or “ing,” Rastle said. “They need to know that’s a meaningful unit,” she said. Some phonics programs explicitly teach these suffixes as part of early reading instruction, she added.
The complexity of words only increases from there. In a recent analysis of 1,200 children’s books designed for ages 7 and up, Rastle and her colleagues found over 100,000 unique words—most of which included multiple morphemes.
“If you know something about morphology, it dramatically lessens the learning load of learning new words,” she said.
Take the word “unhappiness,” for example. The prefix “un” means not, while the suffix “ness” represents a state or condition. If children know the meaning of these word parts, they may have an easier time understanding that “unhappiness,” means the state of being not happy—even if they have never seen the word before.
Children tend to pick up this knowledge implicitly, through exposure to the same morphemes in different words, Rastle said. “But the key is, it takes a long time, and you have to read a lot,” she added.
Some studies have shown that explicitly teaching the structure of words can improve students’ reading ability.
Particularly for English learners who speak languages with Latin or Greek influences, including Spanish, morphology can help them recognize these cross-linguistic relationships.
A 2010 metanalysis focused on students in grades pre-K-8 found that, on average, interventions containing morphology instruction had a modest effect on word reading, spelling, and vocabulary knowledge, when compared to usual classroom instruction.
Still, spending time on morphology might not give teachers more bang for their buck than other interventions.
Some studies in the analysis also compared morphology instruction to an alternative approach, in which researchers trained teachers in the second group on a different type of intervention—such as phonological awareness, or general vocabulary instruction. But there were no statistically significant differences between morphology instruction and these other treatments for word reading or spelling.
When it came to improving students’ vocabulary knowledge, though, morphology instruction had a small edge over other interventions.
Because morphology instruction breaks down words into meaningful parts, it can be a way of “bootstrapping” the English language, said Kieffer—an approach that can be especially helpful for English learners.
“Academic language is really morphologically complex,” Kieffer said. “Particularly for English learners who speak languages with Latin or Greek influences, including Spanish, morphology can help them recognize these cross-linguistic relationships.”
Identifying similar root words across languages is one way that Caitlin Woodburn, a 5th grade EL teacher in Metro Nashville public schools, uses morphology in her instruction. “I think I’ve used the hashtag ‘praise the cognate’ before,” she said, referencing words that have the same origin in different languages.
She also explicitly teaches her students how morphology is linked to parts of speech. The words confusion and confused share the same root, but the “ion” ending indicates a noun, while “confused” is an adjective.
In a 2014 paper, Kieffer and his colleagues tested the effect of a 20-week vocabulary intervention for 6th graders across 14 schools in California, in which about 70 percent of students spoke a language other than English at home. Teachers taught students additional meanings and uses of the words and did morphological analyses with students.
At the end of the intervention, students showed moderate improvement in academic word mastery and a small improvement in reading academic text with academic words, compared to a control group.
What teachers can do
As with other elements of reading, there’s no set amount of time that a teacher should or should not be spending on morphology, said Rastle. Teachers have limited minutes in a day, she said. “You’ve got to think about what the purpose of that instruction is, and what it displaces,” Rastle said.
One thing morphology shouldn’t ever displace is phonics instruction in the early grades, Rastle said. Without a foundational understanding of how letters represent sounds, students are blocked from accessing text, she said.
“I don’t know that [morphology] needs to be a huge focus, among all the other things that teachers need to do in reading instruction,” said Kieffer. “In some sense, it’s just priming students to be more metalinguistic.”
Still, he said, morphology instruction might benefit students who are struggling with decoding multisyllabic words, or students who need to further develop their academic vocabulary, said Kieffer.
The Institute of Education Sciences’ Practice Guide for reading interventions in grades 4-9, recommendations which Kieffer helped author, suggests teaching common prefixes and suffixes to help students decode—and derive the meaning of—multisyllabic words. (IES is the research division of the U.S. Department of Education.)
Some school systems have integrated this kind of morphology instruction into whole-class lessons for all students.
Arkansas has developed a “word attack” protocol, which teachers start using in 3rd grade, said Dianna Herring, the K-12 Science Specialist at the Arkansas River Educational Service Cooperative, who has supported Lancelin’s use of the protocol with her 9th graders in the Pine Bluff district.
Teachers explicitly teach prefixes, suffixes, and base words related to classroom content. In 5th grade science, for example, students might learn the affix “sphere,” meaning a broadly spherical object or region. They can use that knowledge to understand the words, “atmosphere,” “hydrosphere,” and “biosphere,” Herring said. Knowledge of the prefix “bio” could then lead them to a deeper understanding of words like “biography,” or “biological.”
“Instead of just teaching that one word in isolation, we’re teaching those morphemes or those word parts, so every time they see those word parts now, it’s easier for them to assign meaning to that,” she said.
Still, which prefixes and suffixes to teach is another open question, said Rastle. “Of the hundred odd suffixes, many of them don’t occur very often, and they’re not consistent in their meaning,” she said.
If teachers are going to spend time on these word parts in class, Rastle suggested focusing on ones that are used often and have consistent meanings—like “ly,” or “ness.” (The IES Practice Guide also provides a list of most frequently occurring prefixes and suffixes.)
Morphology instruction should also be meaningful and contextualized, said Kieffer. The words that students are deconstructing should be related to the content they’re learning—like the science words in Lancelin’s classroom in Arkansas.
“It takes planning and work, because ‘here’s a list of works with ‘tion’ is easier to do,’” Kieffer said, but probably less effective.
Connecting this word-level instruction with the text that students read has benefits, Lancelin said: “It’s making it easier for them to want to read.”