Journal of Child Language


Explaining quantitative variation in the rate of Optional Infinitive errors across languages: A comparison of MOSAIC and the Variational Learning Model*


a1 University of Liverpool

a2 Brunel University


In this study, we use corpus analysis and computational modelling techniques to compare two recent accounts of the OI stage: Legate & Yang's (2007) Variational Learning Model and Freudenthal, Pine & Gobet's (2006) Model of Syntax Acquisition in Children. We first assess the extent to which each of these accounts can explain the level of OI errors across five different languages (English, Dutch, German, French and Spanish). We then differentiate between the two accounts by testing their predictions about the relation between children's OI errors and the distribution of infinitival verb forms in the input language. We conclude that, although both accounts fit the cross-linguistic patterning of OI errors reasonably well, only MOSAIC is able to explain why verbs that occur more frequently as infinitives than as finite verb forms in the input also occur more frequently as OI errors than as correct finite verb forms in the children's output.

(Received December 19 2008)

(Revised August 14 2009)

(Accepted December 05 2009)

(Online publication March 25 2010)


c1 Address for correspondence:Daniel Freudenthal, School of Psychology, University of Liverpool, Bedford Street South Liverpool, L69 7ZA, United Kingdom. tel: 0151 794 1108; e-mail:


[*] We would like to thank the Max Planck Institute for Evolutionary Anthropology, Leipzig for allowing us access to the Leo Corpus. This research was funded by the ESRC under Grant Number RES-062-23-1348.