The data consist of quantitative information on the proportion of children (aged 2-5yrs) who produced correct past tense verb forms, and associated errors, for a large number of early learned verbs. Children (N = 908) between the ages of 2;6 and 5;5 (years;months) were tested on their ability to produce the simple past tense using two sentence completion paradigms. One paradigm involved producing a past tense form in response to a modelled progressive verb form (Inflection from form); the other involved producing a past tense form to describe a simple animation with no prior verb modelling (Inflection from meaning). 300 target verbs were elicited in the Inflection from form task, and 120 target verbs in the Inflection from meaning task. Children's responses were coded according to their accuracy and a variety of error types. For each verb, the mean proportion of correct responses, use of uninflected verb forms, and overregularisation errors on irregular verbs are reported, along with the number of children attempting each verb in each age group (2;6-3;5, 3;6-4;5, 4;6-5;5) and on each task.On the whole forming the past tense in English is predictable (add '-ed') but there are many exceptions that children need to learn (go-went, think-thought). The frequency of the verb, its meaning, and its sound pattern influence children's production of errors. However these factors are not well understood, and they change as children grow up. In this project, an investigation of the earliest stages of past tense acquisition in English will be carried out using two tasks that encourage 2-5 year-olds to produce past tense forms. The data will be analysed with reference to a wide range of frequency, sound and meaning properties of verbs. Analysing all of these factors in a single study will provide a much more accurate picture of the acquisition process than is currently available, and allow evaluation of current theories of past tense acquisition. A database documenting the children's performance on 300 different verbs and categorising the verbs on a large number of established and new properties will be made available to the research community. This database can then be used to form the basis for future research on English typically-developing and language-disordered populations, and to inform research on other languages.

Children (N = 908) between the ages of 2;6 and 5;5 (years;months) were tested on their ability to produce the simple past tense using two sentence completion paradigms. One paradigm involved producing a past tense form in response to a modelled progressive verb form (Inflection from form); the other involved producing a past tense form to describe a simple animation with no prior verb modelling (Inflection from meaning).