BLC THEORY
BLC Theory proposes that individual differences in language proficiency (in both native and nonnative speakers) can poorly be mapped on a single proficiency scale. Instead, they can best be understood and studied in terms of two fundamentally different dimensions:
- Basic Language Cognition (BLC): a person’s ability to comprehend and produce spoken language in situations of everyday life, and
- Extended Language Cognition (ELC): a person’s control of the written language, as taught in school.
By distinguishing BLC from ELC, the theory helps us to answer the following two questions:
- To what extent is it possible for a bilingual (or multilingual) person to attain so-called complete or native proficiency in two (or more) languages?
- To what extent is it possible for both early and late second language (L2) learners to attain so-called native levels of L2 proficiency?
Theoretical Framework
BLC Theory is placed under the umbrella of a non-nativist, non-modular theoretical framework. The non-nativist view has been proposed, since the mid-1980s, by scholars in usage-based linguistics, neural-network psychology, and in work on complex systems. It can be summarized as follows:
- Each language is a complex adaptive system.
- Children learn language mainly in a bottom-up way, through social interaction.
- Learning mechanisms are not specific for language.
- Mental representations of linguistic constructions emerge from processing.
- Network elements are more or less strongly connected.
- Constructions (form – meaning mappings) are more or less abstract.
- There is no principled distinction between grammar and lexis.
Under this view, adult native speakers (and highly proficient nonnative speakers) understand and produce utterances predictively and probabilistically. This is made possible as a result of massive exposure to, and processing of spoken input. Learners do not create, and language users do not possess a mental, rule-based or principle-constrained grammar, as claimed by Chomsky’s generative, nativist school (Hulstijn, 2024, p. 3).
BLC Theory
The theory predicts that, while cognitive factors such as short-term memory capacity and reasoning ability positively affect the acquisition of reading and writing skills in both native and nonnative speakers, they do not play a significant role in the acquisition of speech processing, in either native or nonnative speakers. Contrary to folk wisdom, one must not be smart to learn to understand and produce speech in a nonnative language. For a detailed presentation of the theory, see the publications listed below.
BLC Theory was first proposed in a journal article (Hulstijn, 2011) and later presented in a book-length publication (Hulstijn, 2015). A paper published in the journal Languages (2024) provides an update of BLC Theory, offering
(1) some changes in the definitions of the theory’s main constructs,
(2) new explicit predictions, and
(3) implications for empirical research in related areas of scientific inquiry.
In 2025, the journal Languages published several solicited peer commentaries. These commentaries were followed by my response (Hulstijn, 2025).
PUBLICATIONS
Articles
Hulstijn, J. (2025). Response to open peer commentaries of Hulstijn’s (2024) update of BLC Theory. Languages, 10 (5), 111. Download
Hulstijn, J.H. (2024). Predictions of individual differences in the acquisition of native and non-native languages: An update of BLC Theory. Languages, 9 (5), 173. Download
Hulstijn, J.H. (2020). Proximate and ultimate explanations of individual differences in language use and language acquisition. Dutch Journal of Applied Linguistics, 9 (1/2), 21-27. Download
Hulstijn, J.H. (2019). An individual-differences framework for comparing nonnative with native speakers: Perspectives from BLC Theory. Language Learning, 69:S1, 157-183. Download
Hulstijn, J.H. (2017). Syntactic patterns in the speech of native speakers of Dutch, differing in age and level of education and profession: A pilot study exploring the size of shared language knowledge. Linguistics in Amsterdam, 10, 1, 60-90. Download
Hulstijn, J.H. (2012). The construct of language proficiency in the study of bilingualism from a cognitive perspective. Bilingualism: Language and Cognition, 15, 422-433. Download
Hulstijn, J.H. (2011). Language proficiency in native and nonnative speakers: An agenda for research and suggestions for second-language assessment. Language Assessment Quarterly, 8, 229-249. Download
Book
Hulstijn, J. H. (2015). Language proficiency in native and non-native speakers: Theory and research. Amsterdam: John Benjamins Publishing Company.
List of errata. Download
