What are Brown's 14 grammatical morphemes?

Brown (1973) identified 14 grammatical morphemes that typically developing English-speaking children acquire in a stable order between roughly 19 and 50 months of age. The list includes the present progressive -ing, prepositions in and on, regular plural -s, irregular past tense, possessive -'s, articles, regular past -ed, regular and irregular third-person singular -s, contractible and uncontractible copulas, and contractible and uncontractible auxiliaries. Mastery is defined as correct use in ≥90% of obligatory contexts across three consecutive language samples.

How do I use this tracker?

Tick off each morpheme as you observe it in the child's spontaneous language sample. The tracker shows you live progress (observed vs. not observed), the percent of the inventory mastered, and the first stage that still has un-mastered morphemes — that is your goal-selection starting point. Use the 'Export PDF' button to drop a one-page summary into the child's chart.

Does this replace a full language sample analysis?

No. The morpheme inventory tracker is a structured checklist for organising what you already heard in a language sample. It does not transcribe the sample, count morphemes, or compute MLU. Use it alongside the MLU Calculator and Lexical Diversity Calculator on the same transcript.

How do I decide whether a morpheme is observed?

Brown's rule of thumb is correct use in 90% of obligatory contexts across three consecutive samples. For a single screening session, most clinicians treat a morpheme as 'observed' if the child produces it correctly at least once in an obligatory context within the sample. Be conservative — if you only heard one ambiguous instance, leave the morpheme unchecked and note it in your follow-up plan.

Why is the order of acquisition important?

The order is remarkably stable across typically developing children, even though the *age* at which each morpheme is mastered varies widely. Knowing the order lets you select therapy targets that sit just above the child's current productive control — pick one or two morphemes from the next stage up rather than skipping ahead to morphemes the child is not yet ready for.

Can I use this tracker with bilingual children?

Brown's 14 morphemes were derived from monolingual English-speaking children. Bilingual children distribute their grammatical development across two languages and may show different patterns of acquisition. Use the tracker as a structured way to record what you heard in each language separately, but do not interpret the percent observed against monolingual age norms without caution.

Yes. The tracker runs entirely in your browser. Nothing you tick is sent to our servers. The PDF you export is generated client-side. Close the tab and the state is gone.

ToolsConductScience tool

Brown 1973Free in-browser calculator

Morpheme Inventory Tracker.

Tick off Brown's 14 grammatical morphemes as you observe them in a language sample. The tracker shows live progress, identifies the first un-mastered Brown stage, and exports a one-page PDF you can drop into the chart — instantly, in your browser.

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Validated2026-04-08

CitableMethods and citation included

When to use

Recording which of Brown's 14 morphemes a child has produced in a language sample
Selecting morpheme-level therapy targets after a screening assessment
Tracking progress on morpheme acquisition across therapy cycles
Teaching SLP graduate students Brown's 14 morphemes with worked examples
Generating a one-page chart-ready PDF summary of morpheme status
Quickly identifying the first un-mastered Brown stage to scope IEP goals

Do not use for

Replacing a full language sample analysis — the tracker is a checklist, not a parser
Diagnosing language disorder from a single screening — Brown's mastery criterion requires three consecutive samples
Comparing bilingual children to monolingual age norms without separate sampling in each language
Calculating MLU or lexical diversity — use the dedicated calculators on the same transcript

Order of acquisition is stable; age of acquisition is not

The order in which Brown's 14 morphemes emerge replicates across children. The age at which any individual morpheme is mastered varies widely. Trust the order when picking targets; do not over-interpret the age ranges as hard cut-offs.

Mastery is not the same as observed

Brown defined mastery as correct use in ≥90% of obligatory contexts across three consecutive samples. A single observation in a screening sample is *emergence*, not mastery. Re-sample to confirm before discharging a goal.

Target the next stage, not the missing stage

If a child has every Stage II morpheme but no Stage III morphemes, target Stage III — not Stage IV or Stage V. Skipping ahead violates the stable order of acquisition and pulls the child outside their zone of proximal development.

Distinguish contractible from uncontractible

"He is happy" → uncontractible copula (cannot say "he's happy" without the contraction). "There he is" → also uncontractible. "He's happy" → contractible copula. The distinction matters: contractible forms appear later than uncontractible forms.

Do not double-count obligatory contexts

A morpheme either appears in an obligatory context or it does not. If the child says "two dog" in a context obligating "two dogs", that is *one* missed obligatory context, not two. Be careful when scoring obligatory contexts manually.

Method

The morpheme list, order of acquisition, and approximate age ranges are taken from Brown (1973) Table 38 and refined by Miller & Chapman (1981). Brown's stage assignments follow the standard textbook mapping (Owens 2020). Mastery is defined per Brown (1973) as correct use in ≥90% of obligatory contexts across three consecutive language samples; the tracker treats *observed* as 'at least one correct production in an obligatory context' and prompts the clinician to re-sample for mastery.

Validated

Last validated 2026-04-08. Calculations are designed for planning and documentation support; verify procurement decisions against manufacturer specifications or institutional SOPs.

How to cite

How to Cite

ConductScience Morpheme Inventory Tracker (v1.0). ConductScience, Inc. 2026. Available at: https://conductscience.com/tools/morpheme-inventory-tracker

Brown R. A First Language: The Early Stages. Harvard University Press; 1973.

Miller JF, Chapman RS. The relation between age and mean length of utterance in morphemes. Journal of Speech and Hearing Research. 1981;24(2):154-161. doi:10.1044/jshr.2402.154

Owens RE. Language Development: An Introduction. 10th ed. Pearson; 2020.

Pavelko SL, Owens RE. Sampling Utterances and Grammatical Analysis Revised (SUGAR): New normative values for language sample analysis measures. LSHSS. 2017;48(3):197-215. doi:10.1044/2017_LSHSS-17-0022

What Are Brown's 14 Morphemes?

Brown's 14 morphemes are the grammatical inflections and function words that mark the beginning of true syntactic development in English-speaking children. They include three prepositions, three present-tense verb inflections, two past-tense forms, four forms of *be*, the regular plural -s, the possessive -'s, and articles.

Why they matter. A child can produce many words without producing any of these morphemes — telegraphic speech ("baby eat cookie") is built entirely from content words. Once a child starts adding morphemes ("baby is eating the cookie"), they have moved out of telegraphic speech and into productive grammar. Tracking which morphemes have emerged is the most direct way to measure where in early grammatical development a child sits.

The stable order. Brown (1973) showed that the order of acquisition is remarkably stable across children, even though the *age* at which each morpheme is mastered varies. Present progressive -ing comes first; the contractible auxiliary comes last. This stability is what makes the inventory clinically useful: you can predict, with reasonable confidence, which morpheme should emerge next.

How to Use This Tracker

The tracker is a structured checklist over Brown's 14 morphemes:

Tick the morphemes you observed. Walk through the child's language sample (or your session notes) and check off each morpheme as you find an instance of it. Use the *examples* under each morpheme to make sure you are recognising it correctly.
Watch the live summary. As you tick boxes, the tracker updates the observed count, the percent of the inventory mastered, and the first un-mastered Brown's stage. That stage is your goal-selection starting point.
Filter by Brown's stage. Use the stage filter to focus on the morphemes you expect a child of a given developmental level to be producing. Stage II (preschool) focuses on the four earliest morphemes; Stage V+ rounds out the inventory.
Export the PDF. When you are done, click *Export PDF* to generate a one-page summary you can drop into the chart or share with a parent. The PDF lists each morpheme, its status (observed / not observed), its acquisition order, and the example utterances.

Selecting Therapy Targets from the Inventory

Once you know which morphemes the child has and has not produced, you can pick targets. Two principles:

1. Target the next stage, not the current stage. A child in Stage II already has the present progressive -ing and prepositions *in* and *on*. Do not target those — pick morphemes from Stage III (irregular past tense, possessive -'s) as the next emerging targets. Stay in the child's zone of proximal development. 2. Pick one or two morphemes per goal cycle. Trying to teach all 14 morphemes simultaneously dilutes intervention. Pick one or two morphemes that are emergent (occasional correct use, not yet mastered) and write SMART goals against them. Re-evaluate the inventory after 4-6 weeks of therapy.

Mastery criterion. Brown defined mastery as ≥90% correct use in obligatory contexts across three consecutive samples. For tracking purposes, treat *observed* in this tool as 'I have seen this morpheme correctly produced' — not full mastery. Re-collect samples regularly to confirm mastery before moving on.

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