Orton-Gillingham morphology: what it is and why it matters for struggling readers

Last updated 2026-07-10

What is morphology, and where does it fit in Orton-Gillingham?

Morphology is the study of morphemes, the smallest units of meaning in a word. The word "unhappiness" has three: "un" (not), "happy" (the root), and "ness" (a quality or state). When a child can spot those parts, she doesn't have to memorize the word whole. She reads it by meaning and structure.

Orton-Gillingham is a structured literacy approach built on one idea: reading is a skill, not a natural process, and most kids who struggle need explicit, sequential, multisensory instruction in how English actually works ^[1]. The full OG scope covers phonology, phonics, fluency, vocabulary, and morphology. Phonics gets most of the press. Morphology is the part that shows up around second grade and picks up speed in third through fifth, which is exactly when reading-to-learn demands spike.

In a formal OG lesson, morphology looks like this. The teacher introduces a Latin root (say, "rupt," meaning to break), shows how it appears in "interrupt," "rupture," and "erupt," then has the student build, spell, and define words using that root. The multisensory element stays: saying it aloud, tapping syllables, writing in sand or on a whiteboard. What changes is the unit of analysis. Instead of a phoneme-grapheme pair, the student works with a morpheme-meaning pair.

This isn't a new add-on. Samuel T. Orton and Anna Gillingham's original work in the 1930s and 1940s included word structure study, Latin and Greek combining forms among it, because they saw that roughly 60 percent of English words with more than one syllable have a Latin or Greek origin ^[2]. Modern OG-derived programs like Wilson Reading System, Barton Reading and Spelling, and SPIRE all carry morphology strands, though the depth and pacing vary.

Why does morphology instruction help kids with dyslexia specifically?

Kids with dyslexia have a documented weakness in phonological processing, the ability to hear and manipulate the sound segments of words ^[3]. Phonics targets that weakness head-on. But phonological processing isn't the only route into a word. Morphological awareness is a partly separate skill, and several studies show it predicts reading ability over and above phonological awareness, especially for older readers.

A 2007 meta-analysis by Carlisle in Scientific Studies of Reading examined 30 studies on morphological awareness and found it a significant unique predictor of reading comprehension in grades 2 through 8 ^[4]. That matters because many students with dyslexia plateau once phonics-only instruction finishes. They can decode short words but fall apart on multisyllabic words like "microscope" or "benefactor." Morphology gives them a second lever.

The mechanism is simple. When a student knows that "micro" means small and "scope" means to look, she can read "microscope" without grinding through every letter-sound pair under pressure. She gets the meaning for free. That pays off in content-area reading, where academic vocabulary is mostly Latinate. A 2013 meta-analysis by Goodwin and Ahn found morphological instruction produced an average effect size of 0.49 on morphological awareness and 0.33 on reading comprehension, real, measurable gains, not marginal ones ^[5].

For students with phonological dyslexia in particular, morphology can be a genuine compensatory strategy. Not a workaround that dodges reading instruction, but an added layer that makes the whole system more redundant and resilient. When the phonological route is slow, the morphological-semantic route steps in.

One honest caveat. Morphology instruction works best after a student has a solid phonics base, roughly first- or second-grade decoding. Throwing Latin roots at a child who can't yet blend consonant clusters is the wrong sequence.

What are the core morphology concepts taught in an OG program?

OG morphology moves through these layers in sequence.

Compound words come first, usually in late kindergarten or early first grade. "Sunshine," "bedroom," "cupcake." Each part is a free morpheme, meaning it can stand alone as a word. This is the concrete entry point.

Inflectional suffixes come next: -s, -es, -ed, -ing, -er, -est. These don't change the word's part of speech; they signal number or tense. A child who understands that "-ed" marks past tense doesn't have to memorize "walked" and "jumped" separately.

Derivational suffixes are harder because they can change part of speech. "-ness" turns an adjective into a noun. "-ful" turns a noun into an adjective. "-ly" turns an adjective into an adverb. OG programs sequence these so a student builds the concept of word families before facing the full list.

Prefixes follow a similar path. High-frequency ones like "un-," "re-," "pre-," "mis-," and "dis-" appear early. A student who knows "un-" can instantly double her reading vocabulary for any root she already knows.

Latin and Greek roots are the backbone of advanced OG morphology. Common Latin roots include "port" (carry), "dict" (say), "rupt" (break), "scrib/script" (write), "vis" (see), and "aud" (hear). Greek combining forms include "graph" (write), "phon" (sound), "bio" (life), "geo" (earth), "therm" (heat), and "chron" (time). A student who knows 20 high-frequency roots can decode and infer meaning for hundreds of words.

The table below shows a sample OG morphology scope and the approximate grade level where each layer usually appears.

Morphology Layer	Content	Typical Intro Grade
Compound words	Free morphemes joined	K-1
Inflectional suffixes	-s, -ed, -ing, -er, -est	1
Common derivational suffixes	-ness, -ful, -less, -ly	1-2
Common prefixes	un-, re-, pre-, dis-, mis-	2
Syllable types + affixes combined	open/closed + affixes	2-3
Latin roots	port, dict, rupt, vis, aud	3-4
Greek combining forms	graph, phon, bio, geo	4-5

This sequence follows guidelines from the International Dyslexia Association's Knowledge and Practice Standards ^[1], though individual programs vary in the exact order.

How is OG morphology taught differently from a regular classroom vocabulary lesson?

In most general-education classrooms, vocabulary instruction means this: here are 10 words for the week's unit, write the definitions, use them in sentences. Morphology in that setup is incidental at best.

OG morphology is systematic and explicit. The teacher introduces one morpheme at a time, follows a defined scope and sequence, and keeps the instruction multisensory. The student doesn't just write the word. She says the root, states its meaning, taps the syllables, writes it, reads it in isolation, then reads it in a sentence.

The deductive (or explicit) approach is standard in OG: the teacher says "the root 'port' means to carry," then gives examples. Some OG-trained teachers also use an inductive approach for morphology specifically, offering "transport," "import," "export," and "portable" and asking the student to find the common element. Research on morphological instruction (Bowers, Kirby & Deacon, 2010) suggests both direct instruction and guided analysis improve outcomes, but direct instruction tends to work better for students with learning disabilities because it reduces cognitive load during the learning phase ^[6].

Another difference: OG morphology connects to spelling rules directly. The rule for dropping a final silent-e before a vowel suffix (-ing, -ed) is a morphophonological rule. The rule for doubling the final consonant in "running" but not "reading" comes down to syllable structure and morpheme boundaries. Teaching morphology this way is one reason OG programs produce stronger spelling outcomes than phonics-only approaches.

A tutor certified in OG also gives immediate corrective feedback morpheme by morpheme, which beats circling a word wrong on a spelling test. If a student misspells "invisible" as "invisable," the teacher walks through the parts: root "vis" (see), prefix "in-" (not), suffix "-ible" (able to be), and pins down which morpheme caused the error. The correction is structural, not rote.

When should a child start morphology work in OG, and how long does it take?

Most OG programs introduce the first morphology concepts around late first or early second grade, once a student has mastered short vowels, basic consonant patterns, and simple blending. That foundation matters because OG morphology still uses phonics knowledge. A student has to read the morpheme before she can analyze its meaning.

For a child with dyslexia who started OG in kindergarten or first grade, morphology becomes a major instructional focus in grades 3 through 5. But "start" doesn't mean "end." Morphology work continues through middle school in structured literacy programs, and some students carry it into high school.

The timeline varies a lot by the child's starting point, the intensity of instruction, and the program. A child getting OG 30 minutes daily, five days a week (an intensive tier) moves through the scope faster than one getting 45 minutes twice a week from a tutor. Research on structured literacy programs generally reports meaningful reading gains after 100 to 200 hours of instruction, and students with more severe profiles often need 300 hours or more ^[7].

Here's the honest expectation. Morphology won't produce overnight fluency gains. The payoff is most visible in standardized reading comprehension scores at grades 3 to 5, and in a student's ability to handle content-area reading (science, social studies) where academic vocabulary is dense. If a struggling reader's tutor or school program hasn't started any morphology by third grade, raise it explicitly.

How does morphology fit into a school IEP or 504 plan for a student with dyslexia?

Under the Individuals with Disabilities Education Act (IDEA), specifically 20 U.S.C. § 1414, a child's IEP must include a statement of present levels of academic achievement, measurable annual goals, and a description of the special education services the school will provide ^[8]. If a child has a reading disability, those services should rest on evidence-based practice.

Morphology instruction is named in the International Dyslexia Association's definition of structured literacy, which the U.S. Department of Education has referenced in guidance as an evidence-based approach for students with dyslexia ^[9]. So a parent can fairly ask: does the IEP's reading service include explicit instruction in phonological awareness, phonics, fluency, vocabulary, comprehension, AND morphology? If the answer is no, that's a gap worth documenting.

A workable IEP goal for morphology might read: "Given a list of 20 grade-level multisyllabic words containing common Latin roots and affixes, the student will correctly decode and define 16 out of 20 (80%) across three consecutive probes by the annual review date." Vague goals like "student will improve reading vocabulary" give you nothing to measure. Ask for specifics.

For a 504 plan, morphology is less likely to be a direct service item (504 covers accommodations, not specially designed instruction). But accommodations like extended time, glossaries, or word banks in content-area classes connect straight to morphological knowledge. A student who hasn't been taught Latin roots leans harder on a glossary in biology class than one who knows what "mitosis" is built from.

If you suspect your child needs a formal evaluation before any of this can happen, request a dyslexia test or learning disability test through the school in writing. Under most state timelines the school has 60 days to respond to that request ^[8].

ReadFlare's free parent advocacy kit includes a sample IEP goal bank with morphology-specific goals you can bring to your next meeting. Download it before the meeting, not after.

What does the research say about morphology instruction and reading outcomes?

The evidence for morphology instruction is solid and has grown a lot since 2000. Here are the findings you should know.

The National Reading Panel's 2000 report named five components of reading instruction: phonemic awareness, phonics, fluency, vocabulary, and comprehension. Morphology wasn't a standalone strand; it sat inside vocabulary and phonics. Since then, the field has largely come to treat morphological awareness as a distinct, teachable skill that deserves its own instructional strand ^[10].

Carlisle's 2007 meta-analysis found morphological awareness predicted reading comprehension from second grade on, even after controlling for vocabulary and phonological awareness ^[4]. That's the point: morphology isn't just riding vocabulary's coattails. It adds something independent.

Goodwin and Ahn's 2013 meta-analysis of 30 intervention studies found morphological instruction improved morphological awareness (effect size 0.49), reading fluency (0.35), reading comprehension (0.33), vocabulary (0.29), and phonological awareness (0.28) ^[5]. Effect sizes in the 0.25 to 0.50 range are educationally meaningful. For comparison, many reading interventions struggle to clear 0.20.

Bowers, Kirby, and Deacon's 2010 review in Review of Educational Research examined morphological instruction across many studies and found significant gains in decoding and spelling when morphology was added to phonological instruction, compared to phonological instruction alone ^[6].

One honest limitation. Most studies use small samples, short durations, and trained researchers delivering the instruction. Whether typical classroom teachers or tutors with varying OG training reproduce these results is less well documented. That gap matters.

What OG-based programs include the strongest morphology component?

Not every program that calls itself OG-based has an equally developed morphology strand. Here's an honest comparison from their published scope and sequence documents.

Wilson Reading System (Wilson Language Training): morphology runs through all 12 steps. Latin roots appear in Steps 9 through 12, and Greek combining forms come in at the advanced levels ^[11]. Wilson is among the most explicit OG-derived programs about word structure. It's built for students in third grade and above with significant reading disabilities.

Barton Reading and Spelling: Barton introduces affixes in Level 4 and builds morphological analysis through Level 10 ^[12]. It's designed for parent and tutor delivery without deep linguistics training. The morphology strand is adequate but lighter than Wilson's upper levels.

LANGUAGE!: includes a structured vocabulary strand with morphemic analysis. Good morphology integration, though its phonics approach differs somewhat from traditional OG.

SPIRE (Specialized Program Individualizing Reading Excellence): covers inflectional and derivational morphology and includes Latin roots at upper levels. Built for small-group school settings.

All About Reading / All About Spelling: strong phonics base, introduces affixes, but carries less Latin and Greek roots content than Wilson or a formal OG tutorial. Best for elementary morphology foundations, not advanced multisyllabic word analysis.

For a student with a double deficit dyslexia profile (weak phonology AND weak rapid naming), morphology in a program like Wilson can be especially useful because it adds a semantic route to word recognition that doesn't lean entirely on phonological speed.

Cost matters too. Individual OG tutoring typically runs $60 to $150 an hour in the U.S., depending on the tutor's certification level and location. Wilson-certified tutors tend toward the higher end. If the school provides OG-based services through the IEP, it comes at no cost to the family. That's worth fighting for.

How can parents teach or reinforce morphology at home without an OG certification?

You don't need a certification to do useful morphology work at home. You need to be organized and consistent.

Start with high-frequency prefixes. Print a simple list of the 20 most common English prefixes and their meanings. Vocabulary researchers like Isabel Beck and Margaret McKeown identify "un-," "re-," "in-/im-/ir-/il-," and "dis-" as the four prefixes that alone account for roughly 65 percent of all prefixed words in school texts ^[2]. That's a high-payoff starting point.

Play "word detective." When your child hits an unfamiliar word, don't just hand over the definition. Ask: do you see a part you recognize? What does that part mean? What might the whole word mean? It takes an extra 60 seconds and builds the habit of morphological analysis.

Use a word wall or a notebook divided by roots. Every time a new word with "port" shows up (transport, import, export, portable, porter), add it to the "port = carry" section. Over weeks, the child builds a network of words instead of a list of isolated definitions.

For spelling, teach the morpheme-boundary rules out loud. "Running" doubles the n because the suffix "-ing" follows a closed syllable that ends in a single consonant after a short vowel. Teaching that rule morphologically heads off a whole class of spelling errors. Flashcard practice works well for drilling high-frequency roots; you can find printable sight word flashcards and adapt them for morpheme cards.

Know what you shouldn't skip. Home morphology work supplements structured phonics instruction for a child with dyslexia. It doesn't replace it. If your child still struggles with basic dolch sight words or blending, those come first. Morphology amplifies a reading base. It can't substitute for one.

ReadFlare's free reading toolkit includes printable morpheme cards organized by Latin root families, which parents use alongside tutor sessions to reinforce work between appointments.

How does morphology instruction connect to reading comprehension for older students?

This is where morphology pays the biggest dividend, and where its absence does the most damage.

Between third and fifth grade, texts shift from mostly phonetically regular narrative to content-area reading packed with academic vocabulary. The vocabulary of science, history, and math textbooks is roughly 90 percent Latinate or Greek in origin ^[2]. A fifth grader who doesn't know that "aqua" means water, "terra" means earth, and "scope" means to look has a much harder time with "aquatic," "extraterrestrial," and "microscope" than a peer who does.

Morphological knowledge also helps comprehension through fluency. A student who instantly parses "incomprehensible" as "in" (not) + "comprehend" (to understand) + "-ible" (able to be) reads it faster and with less working memory load. That freed-up capacity goes to understanding the sentence.

For students with surface dyslexia, who over-rely on phonics and struggle with irregular words, morphology gives them a structure for attacking longer words that phonics alone can't fully handle. "Necessary," "psychology," and "February" get more manageable once you see their morphological structure, even when the phonics is irregular.

For students with rapid naming deficit, where slow retrieval of word forms is the core problem, morphological chunking can help because the student retrieves a larger, more meaningful unit (a root plus affix) instead of letter-by-letter sounds. The evidence on this specific mechanism is still emerging, but OG practitioners report it consistently.

On standardized testing, the NAEP and most state reading assessments introduce informational text starting in grade 4, with heavy academic vocabulary demands. Students who got explicit morphology instruction through third grade tend to outscore those who didn't on vocabulary subtests. The gap widens in middle school.

What questions should parents ask a tutor or school about their OG morphology instruction?

Ask these before you sign a tutoring contract or accept an IEP service description.

Does the tutor or program have a written scope and sequence for morphology? A vague answer is a red flag. Every structured literacy program should have a documented sequence for when each morpheme type comes in.

Where does my child currently perform on morphological awareness? Some assessments, like subtests of the CTOPP-2, give you a baseline. If a tutor has never assessed morphological awareness, they may not be targeting it well.

How is morphology integrated with phonics, spelling, and vocabulary in lessons? Good OG doesn't treat morphology as a separate Friday activity. It shows up in word analysis, spelling practice, and vocabulary work across each lesson.

Can you show me a sample lesson plan that includes a morphology component? This is a fair request. A tutor who can't produce one probably isn't doing systematic morphology work.

How do you track progress on morphology goals specifically? Data should be coming in on morpheme recognition, correct spelling of morphologically complex words, and using roots to infer meaning.

For school IEPs, add this: Was morphological awareness included in the assessments the school used to determine my child's reading profile? Many standard reading batteries skip morphological awareness. If the school's evaluation only measured phonological awareness, fluency, and comprehension, it may have missed a skill area that needs direct instruction. You can request additional assessments under IDEA ^[8].

If you're unsure whether your child's reading profile points to a broader learning disability picture or specifically a phonological dyslexia profile, a full evaluation is the clearest path forward.

Frequently asked questions

What is morphology in Orton-Gillingham, in simple terms?

Morphology in OG means teaching kids to break words into meaningful parts: prefixes, roots, and suffixes. Instead of sounding out every letter in "unbreakable," a student who knows "un-" means not, "break" is the root, and "-able" means capable of being, can read and understand the word right away. OG programs introduce morphology in a set sequence, starting with compound words and building to Latin and Greek roots.

At what age or grade does morphology instruction start in OG?

Most OG programs introduce the first morphology concepts, compound words and simple inflectional suffixes, in late first grade or early second grade, once a child has a solid phonics foundation. Prefixes and derivational suffixes usually follow in second grade. Latin roots typically begin in third or fourth grade. The sequence assumes the child can already blend and segment syllables reliably.

Does morphology instruction help kids with dyslexia, or is phonics enough?

Phonics is essential for dyslexia, but it isn't the whole picture. Research by Carlisle (2007) and Goodwin and Ahn (2013) found morphological awareness predicts reading comprehension independently of phonological awareness, especially in grades 3 through 8. Students with dyslexia who plateau after phonics instruction often benefit a lot from adding structured morphology work, particularly for multisyllabic academic vocabulary.

What Latin and Greek roots are most important to teach first?

High-frequency Latin roots for early instruction include port (carry), dict (say), rupt (break), vis (see), aud (hear), scrib/script (write), and duct/duc (lead). For Greek, start with graph (write), phon (sound), bio (life), geo (earth), and chron (time). Vocabulary researchers estimate these roughly 20 roots account for several hundred common English words, making them the highest-payoff starting point.

How do I know if my child's OG tutor is actually teaching morphology?

Ask for a copy of the program's scope and sequence and confirm morphology is listed. Ask to see a sample lesson plan that includes a morphology component. Ask how the tutor tracks progress on word-part analysis specifically. If the tutor spends all lesson time on phoneme-grapheme pairs and basic phonics with no roots or affixes work, and the child is past second grade, that's a gap worth addressing directly.

Can morphology instruction help with spelling more than reading?

Yes, substantially. Many of the most common English spelling errors involve morpheme boundaries: doubling rules, silent-e dropping, and irregular plurals all have morphophonological explanations. Teaching a student that the suffix "-ible" (not "-able") attaches to Latin roots, or that "-tion" always signals a Latinate noun, cuts a big category of spelling errors that pure phonics rules can't fully explain.

What's the difference between morphology and phonics in OG?

Phonics maps letters to sounds. Morphology maps word parts to meanings. In OG, phonics usually comes first and morphology builds on top of it. A child needs to read and spell the morpheme before she can analyze its meaning in a network of related words. Both strands work together: morphology instruction reinforces phonics by showing how spelling patterns follow morpheme boundaries rather than appearing arbitrary.

Can I request morphology instruction in my child's IEP?

Yes. Under IDEA (20 U.S.C. § 1414), an IEP must include specially designed instruction based on the child's assessed needs. If your child's evaluation shows weak morphological awareness or poor comprehension of multisyllabic words, you can ask for explicit morphology instruction as part of the reading service. Ask for a measurable annual goal tied to specific morpheme types, not a general vocabulary goal.

How long does it take to see results from OG morphology instruction?

Most research on structured literacy programs reports measurable gains after 100 to 200 hours of intervention for students with average-severity dyslexia. Morphology-specific gains in reading comprehension and vocabulary are often most visible on standardized assessments at the end of third, fourth, or fifth grade. Don't expect big vocabulary test changes after four weeks. The gains compound over months.

Are there free resources for teaching OG morphology at home?

Several useful free resources exist. The International Dyslexia Association (dyslexiaida.org) has fact sheets on structured literacy and morphology. ReadWorks and Vocabulary.com both have academic vocabulary tools with morpheme-based word groupings. For printable morpheme cards organized by Latin root families, ReadFlare's free reading toolkit is a practical starting point for parents working alongside a tutor.

Is morphology part of the science of reading?

Yes. The science of reading framework covers phonological awareness, phonics, fluency, vocabulary, and comprehension, and leading researchers and the International Dyslexia Association's Knowledge and Practice Standards explicitly include morphological awareness as a foundational language skill. Structured literacy, the evidence-based approach endorsed by the IDA and referenced in federal guidance, requires morphology instruction as part of a complete program.

Which is better for morphology: Wilson Reading System or Barton?

Wilson has a more intensive, extensive morphology strand, particularly for Latin roots in Steps 9 through 12. Barton is more accessible for parents to deliver without formal training and covers affixes adequately through Level 10, but its roots content is thinner. If the child is in middle school with significant vocabulary gaps, Wilson's upper levels are worth the extra cost of a trained provider. For elementary grades, Barton is usually enough.

Does morphology instruction look different for English language learners with dyslexia?

It can, because a student whose home language is Spanish, French, or another Romance language may already carry implicit knowledge of Latin roots that an English-only speaker lacks. A skilled OG practitioner will draw on that prior knowledge explicitly, for example connecting "acuático" to "aquatic" through the shared Latin root "aqua." The scope and sequence stays the same, but the bridge to prior language knowledge is an important added layer.

Sources

1. International Dyslexia Association, Knowledge and Practice Standards for Teachers of Reading: Structured literacy includes explicit instruction in phonology, phonics, fluency, vocabulary, morphology, and syntax; OG is identified as a structured literacy approach.
2. Beck, McKeown & Kucan, Bringing Words to Life (Guilford Press); Bowers & Cooke, morpheme frequency estimates: Roughly 60 percent of English multisyllabic words derive from Latin or Greek; four prefixes (un-, re-, in-, dis-) account for ~65 percent of all prefixed words in school texts.
3. National Institute of Child Health and Human Development, Dyslexia Information Page: Dyslexia is characterized by difficulties with accurate and fluent word recognition, poor spelling, and poor decoding abilities, rooted in phonological processing deficits.
4. Carlisle, J.F. (2007). Fostering morphological processing, vocabulary development, and reading comprehension. Scientific Studies of Reading, 11(4), 279–310.: Morphological awareness is a significant unique predictor of reading comprehension from second through eighth grade, over and above phonological awareness and vocabulary.
5. Goodwin, A.P. & Ahn, S. (2013). A meta-analysis of morphological interventions in English. Scientific Studies of Reading, 17(4), 257–285.: Morphological instruction produced average effect sizes of 0.49 on morphological awareness, 0.33 on reading comprehension, 0.35 on fluency, and 0.29 on vocabulary across 30 intervention studies.
6. Bowers, P.N., Kirby, J.R., & Deacon, S.H. (2010). The effects of morphological instruction on literacy skills. Review of Educational Research, 80(2), 144–179.: Morphological instruction added to phonological instruction produced significant gains in decoding and spelling for students with reading disabilities; direct instruction reduced cognitive load compared to discovery approaches.
7. International Dyslexia Association, Dyslexia in the Classroom fact sheet: Students with dyslexia typically require 100 to 300 or more hours of intensive structured literacy intervention depending on severity.
8. Individuals with Disabilities Education Act, 20 U.S.C. § 1414: IEPs must include present levels of performance, measurable annual goals, and a description of specially designed instruction; schools must respond to parent evaluation requests within applicable state timelines.
9. U.S. Department of Education, Office of Special Education Programs, IDEA Topic Briefs: Federal guidance references structured literacy and evidence-based reading practices for students with learning disabilities, including dyslexia.
10. National Institute of Child Health and Human Development, Report of the National Reading Panel (2000): The National Reading Panel identified five core components of reading instruction: phonemic awareness, phonics, fluency, vocabulary, and comprehension; morphology has been increasingly recognized as a distinct component since this report.
11. Wilson Language Training, Wilson Reading System Scope and Sequence: Wilson Reading System integrates morphology across all 12 steps, with Latin roots introduced in Steps 9–12 and Greek combining forms at advanced levels.
12. Barton Reading and Spelling System, Level descriptions: Barton Reading and Spelling introduces affixes in Level 4 and builds morphological analysis through Level 10.