Published online by Cambridge University Press: 26 September 2008
Two young children were studied from the period when their expressive lexicons were approximately 30 words until they showed productive two-word positional patterns in their speech. Word combinations meeting the criteria for positional productive, positional associative and groping patterns were identified and the period during which the words appearing in these patterns were acquired was then determined. Words used in positional productive patterns had generally emerged in the children's speech before those used in associative or groping patterns. When several words that could play a particular semantic role (e.g. actor) were already well established in the child's lexicon, positional productive patterns that were somewhat broader in scope appeared as early as lexically based patterns.