Linguistic experience and processing speed differentially affect lexical retrieval and structural assembly during language production.

Our ability to produce words and sentences relies on lexical retrieval and structural assembly processes, which are supported by domain-general skills. In the present study, we adopted an individual-differences approach to examine how linguistic experience and domain-general skills jointly contribute to language production at different levels of complexity. Our participants (n = 169) completed three production tasks that capitalized on lexical retrieval (picture naming) and structural assembly (phrase generation and sentence generation) processes, respectively. In addition, they completed 15 tests measuring linguistic experience, processing speed, working memory, and nonverbal reasoning. Our analyses of speech onset latencies and speech durations showed that linguistic experience was primarily associated with faster speech initiation, particularly in picture naming, consistent with its role in supporting efficient lexical access. In contrast, processing speed emerged as a robust predictor of both earlier speech initiation and shorter utterance durations, with effects that were disproportionately larger for phrase and sentence production than for picture naming, highlighting its role in coordinating multiword structural assembly under time pressure. Working memory was linked to a redistribution of planning across time, with higher capacity associated with longer onset latencies but shorter speech durations. By integrating multiple predictors, our study provides novel insights into the cognitive architecture underlying language production and highlights the value of a holistic individual-differences approach.