Language acquisition requires a child to effectively structure and process sensory input. Language is heavily based on regularities and statistical probabilities in phonemic patterns, syntactic structures, semantics, and pragmatics. Considering the remarkable diversity in the manifestation and characteristics of language, it is nothing short of miraculous that most children effortlessly acquire language. Nevertheless, language acquisition varies among individuals and does not always occur without difficulties. Children typically utter their first words around their first birthdays. Late talkers are children who, for no obvious reason, still produce few or no words by the age of two. In this thesis, I explore domain-general mechanisms (i.e., mechanisms shared across different sensory modalities or areas of cognition) that have been suggested to underlie individual differences in language abilities and examine whether these mechanisms differ across children with and without a history of late talking. In all the studies included in this thesis, the participants were 7–10- year-old children, half of whom had a history of late talking. By investigating the relationship between the suggested mechanisms and early language development, I also aimed to identify potential candidates that could explain language outcomes in late talkers. In Study I, we observed a relationship between the speed of processing and language abilities but no associations between attentional inhibition and language. In Study II, the learning of regularities was found to be associated with language abilities in children with a history of typical early development but not in late talkers. In Study III, we measured electrical brain responses to sounds; the amplitudes of the responses were found to be associated with language abilities, suggesting that differences in language abilities are related to early-level auditory processing. In Study IV, we observed a relationship between the pronounced within-individual variability in response times and language abilities. Based on this finding, I propose the Intra-Individual Variability hypothesis of language, which suggests that instability in processing linguistic inputs may lead to differences in language abilities. In this thesis, I posit that this hypothesis provides a meaningful framework for interpreting the findings of Study I–III as well.