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Morpheme #5 of 14Brown's Stage II25–46 months

Irregular Past Tense

Irregular past-tense verbs ("went", "ate", "broke") are the fifth of Brown's 14 morphemes, mastered between 25 and 46 months in typical development.

At a glance

Acquisition order
#5 of 14 (Brown 1973)
Symbol / form
irregular past
Brown's stage
II
Typical age of mastery
25–46 months

Mastery is defined as correct use in 90% of obligatory contexts across three consecutive language samples (Brown 1973). Individual variation is wide — these ranges describe typically developing English-speaking children and should be cross-referenced against the primary literature before clinical use.

What this morpheme is

Irregular past-tense verbs are the small set of high-frequency English verbs whose past tense is formed by stem change rather than the regular -ed suffix: "went", "ate", "broke", "saw", "fell", "had", "did", "got", "came". Brown grouped them as a single morpheme because they share the same grammatical function — past-tense marking — and because they reach mastery in roughly the same developmental window. They are interesting because they appear earlier than the regular -ed suffix in production, which is counterintuitive: children memorise high-frequency irregulars as whole forms before they extract the regular rule.

Acquisition trajectory

The trajectory is U-shaped, which Brown identified as one of the most striking patterns in his data and which has been replicated in dozens of studies since. Children produce irregular past forms correctly from late Stage II onward — "went", "ate", "got" — because they have memorised them as whole-word lexical items. Then, around 30–36 months, they begin to extract the regular -ed rule and overgeneralise it to the irregulars they had previously been producing correctly: "goed", "eated", "breaked". The U-shaped pattern is the dip from correct → overgeneralised → correct again, and the recovery to adult-like use can take until age 6 or later for low-frequency irregulars. The order in which individual irregulars are mastered correlates with frequency in caregiver speech, not with phonological complexity, and clinicians should expect long-tail variability across children.

Examples in obligatory context

These are the kinds of child utterances a clinician would code as a correct production of irregular past when scoring a language sample.

  • “I went to the store.”
  • “She ate the cookie.”
  • “I broke the cup.”
  • “He saw the dog.”
  • “The ball fell down.”
  • “We had pizza.”

Common errors during the acquisition window

  • Overgeneralisation of regular -ed: "goed", "eated", "breaked", "falled"
  • Bare stem in obligatory past context: "I go to the store yesterday"
  • Double marking: "wented", "ated", "broked"
  • Substitution of one irregular for another: "I sawed it" for "I saw it"

Many of these errors are developmentally normal during the acquisition window. The clinical signal is persistence past the typical age of mastery, not the presence of any single error in early production.

Clinical relevance and scoring

Irregular past tense is a sensitive morpheme for the school-age extended-optional-infinitive profile of DLD. Children with DLD show fewer overgeneralisations and more bare-stem omissions ("I go yesterday") than typically developing peers — that is, they are stuck before the U-shaped curve rather than progressing through it. Score irregular past tense in a language sample by identifying every obligatory past-tense context with an irregular verb and coding for correct production, overgeneralisation, or bare stem. The two error types tell different developmental stories and should be reported separately. Frequency matters: a child producing "went" correctly but "fell" as "falled" is at a different developmental moment than a child who is bare-stemming both, and the report should reflect that.

“Overgeneralisation and bare-stem omission look like the same surface error to a parent, but they are opposite developmental signals. The child who says "goed" is ahead of the child who says "go" yesterday. Code them as different things.”
Overgeneralisation is not omission

Free tools for scoring this morpheme

MLU Calculator

Paste a language sample and get Mean Length of Utterance in morphemes and words, total utterances, total morphemes, and the matching Brown's stage. Implements Brown (1973) morpheme counting rules and runs entirely in your browser.

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Brown's Stages Lookup

Interactive reference for Brown's (1973) five stages of grammatical development. Look up a stage by child age or MLU, see the MLU range, acquired morphemes, example utterances, and clinical milestones for each stage.

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DSS Calculator

Free Developmental Sentence Scoring (DSS) calculator for speech-language pathologists. Paste 50 sentences, tap weighted points across the eight Lee (1974) grammatical categories — Indefinite Pronouns, Personal Pronouns, Main Verbs, Secondary Verbs, Negatives, Conjunctions, Interrogative Reversals, Wh-Questions — plus the all-correct sentence point, and the calculator returns the live DSS with a per-category breakdown. Mobile-friendly tap-through grid, client-side, no sign-up.

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Related morphemes

#9 · Stage IV

Regular Past -ed

Regular past tense -ed is the ninth of Brown's 14 morphemes, marking past on regular verbs and reaching mastery between 26 and 48 months.

#10 · Stage IV

Regular Third-Person Singular -s

Regular third-person singular -s is the tenth of Brown's 14 morphemes, marking present-tense agreement and reaching mastery between 26 and 46 months.

#11 · Stage V

Irregular Third-Person Singular

Irregular third-person singular forms (does, has) are the eleventh of Brown's 14 morphemes, mastered between 28 and 50 months.

References

  1. Brown, R. (1973). A First Language: The Early Stages. Harvard University Press, pp. 254–271.
  2. Marcus, G. F., Pinker, S., Ullman, M., Hollander, M., Rosen, T. J., & Xu, F. (1992). Overregularization in language acquisition. Monographs of the Society for Research in Child Development, 57(4), 1–182.
  3. Rice, M. L., Wexler, K., & Hershberger, S. (1998). Tense over time: The longitudinal course of tense acquisition in children with specific language impairment. JSLHR, 41(6), 1412–1431.