Simulating optional infinitive errors in child speech through the omission of sentence-internal elements.

Abstract

A new version of the MOSAIC model of syntax acquisition is presented. The modifications to the model aim to address two weaknesses in its earlier simulations of the Optional Infinitive phenomenon: an over-reliance on questions in the input as the source for Optional Infinitive errors, and the use of an utterance-final bias in learning (recency effect), without a corresponding utterance-initial bias (primacy effect). Where the old version only produced utterance-final phrases, the new version of MOSAIC learns from both the left and right edge of the utterance, and associates utterance-initial and utterancefinal phrases. The new model produces both utterance-final phrases and concatenations of utterance-final and utteranceinitial phrases. MOSAIC now also differentiates between phrases learned from declarative and interrogative input. It will be shown that the new version is capable of simulating the Optional Infinitive phenomenon in English and Dutch without relying on interrogative input. Unlike the previous version of MOSAIC, the new version is also capable of simulating cross-linguistic variation in the occurrence of Optional Infinitive errors in Wh-questions.