Grammatical and phonological influences on word order

During the grammatical encoding of spoken multiword utterances, various kinds of information must be used to determine the order of words. For example, whereas in adjective-noun utterances like "red car," word order can be determined on the basis of the word's grammatical class information, in noun-noun utterances like "... by car, bus, or ...," word order cannot be determined on the basis of a word's grammatical class information. We investigated whether a word's phonological properties play a role in grammatical encoding. In four experiments, participants produced multiword utterances in which the words' onset phonology was manipulated. Phonological-onset relatedness yielded inhibitory effects in noun-noun utterances, no effects in noun-adjective utterances, and facilitatory effects in adjective-noun, noun-verb, and adjective-adjective-noun utterances. These results cannot be explained by differences in the stimulus displays used to elicit the utterances and suggest that grammatical encoding is sensitive to the phonological properties of words.