Initial morphological learning in preverbal infants.

How do children learn the internal structure of inflected words? We hypothesized that bound functional morphemes begin to be encoded at the preverbal stage, driven by their frequent occurrence with highly variable roots, and that infants in turn use these morphemes to interpret other words with the same inflections. Using a preferential looking procedure, we showed that French-learning 11-month-olds encoded the frequent French functor /e/, and perceived bare roots and their inflected variants as related forms. In another experiment an added training phase presented an artificial suffix co-occurring with many pseudo-roots. Infants learned the new suffix and used it to interpret novel affixed words that never occurred during the training. These findings demonstrate that initial learning of sub-lexical functors and morphological alternations is frequency-based, without relying on word meaning.