The present investigation is dedicated to the study of the Brazilian Portuguese
children’s morphological knowledge and its relation with levels of mental representations as
postulated by the Representational Redescription model (KARMILOFF-SMITH, 1992). The
data consist of regularized verbal forms, changes of inflectional suffixes as well as lexical novelty
(morphological variant forms) taken from spontaneous speech and of three morphological tests,
which involve derivation and inflection of nonce words, extraction of nonce base from derived
nonce words, and judgment of words as well as a metalinguistic explanation. The survey of
the responses reveals morphological knowledge that goes from sensitivity – morphological
variant forms – to linguistic awareness – morphology tests. Thus, the data pointed to the
plausibility of all the different levels of representation across development. In our view, this
work embodies a first step towards an explanation of the mental representations that underlie
both the comprehension and production of children’s growing morphological knowledge and
goes beyond the simple implicit/explicit dichotomy used in most previous work
