Morphological cues vs. number of nominals in learning verb types in Turkish: The syntactic bootstrapping mechanism revisited

Abstract

The syntactic bootstrapping mechanism of verb learning was evaluated against child-directed speech in Turkish, a language with rich morphology, nominal ellipsis and free word order. Machine-learning algorithms were run on transcribed caregiver speech directed to two Turkish learners (one hour every two weeks between 0;9 to 1;10) of different socioeconomic backgrounds. We found that the number of nominals in child-directed utterances plays a small, but significant, role in classifying transitive and intransitive verbs. Further, we found that accusative morphology on the noun is a strong cue in clustering verb types. We also found that verbal morphology (past tense and bareness of verbs) is useful in distinguishing between different subtypes of intransitive verbs. These results suggest that syntactic bootstrapping mechanisms should be extended to include morphological cues to verb learning in morphologically rich languages.