Word onsets and speech errors. Explaining relative frequencies of segmental substitutions

•There are more speech errors in word onsets than in other positions.•This is assumed to be caused by phonotactic constraints on speech errors.•This hypothesis is tested in a corpus of Dutch speech errors and confirmed.•There is no need to accommodate the effect in models of speech production.•Errors in word onsets and in vowels are more often repaired than other errors.

Consonants in word onsets are, in English and Dutch, more frequently misspoken than consonants in other positions, and also more frequently than expected from the relative numbers of onset consonants and other consonants. We argue here that relative numbers of segments in specific positions in the word is not a valid predictor of relative frequencies of segmental speech errors. A more valid predictor would be the relative number of phonotactically allowed opportunities segments in different positions have to be involved in interactional speech errors. Analysis of segmental speech errors in spontaneous Dutch shows that relative frequencies of interactional substitutions of single segments in vowel positions, and word initial, medial and final consonant positions, may indeed be predicted rather precisely from the allowed opportunities for segments in different positions to be involved in interactional speech errors, and that there is no additional ‘word onset’ effect in these speech errors.