Phonological constraints on the emergence of two-word utterances

Considerable interest has been generated concerning linguistic and cognitive factors influencing the onset of early combinatorial speech. The present diary study provides evidence that, for some children, the transition between the single-word and two-word stages may be governed by phonological constraints. The presence of a phonological selection strategy and consonant harmony rule in one child's developing phonological system is described. Evidence is presented suggesting that this consonant harmony constraint operated across morpheme boundaries. This had the effect not only of delaying the onset of two-word utterances, but also of influencing the selection of words that could occur in word combinations. The implications of these findings for explaining individual variation in the transition from single-word to combinatorial speech are discussed.