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Professor Margaret Deuchar FRSA

Code-switching; bilingualism; language contact; language variation; corpus linguistics
Professor Margaret Deuchar, FRSA

Emeritus Professor of Linguistics, Bangor University

Affiliated Lecturer, Dept of Theoretical and Applied Linguistics



Language contact

Language variation

Corpus linguistics

Departments and Institutes

Theoretical and Applied Linguistics:
Affiliated Lecturer

Research Interests

My research interests are in bilingualism, particularly code-switching and I recently organised an interdisciplinary workshop on code-switching, held in Cambridge on 3-4th October 2016.  This led to the establishment of a code-switching reading group which met regularly in the year 2016-2017 and will continue in 2017-2018.  I have recently completed a book about Welsh-English code-switching to be published by John Benjamins. With a research team at Bangor University we collected bilingual conversations from three groups of bilinguals: Welsh-English, Spanish-English and Welsh-Spanish.  The conversations were transcribed and are made available in the public domain (  Data from the corpora have been used by my collaborators and myself to evaluate competing linguistic theories of code-switching (e.g. Herring et al 2010), to compare code-switching patterns in three bilingual communities (Carter et al 2011), challenge influential views of the boundary between code-switching and borrowing (Stammers & Deuchar 2012) and to establish the key extralinguistic factors influencing the production of code-switching (Deuchar et al forthcoming).  Current work focuses on the choice of the matrix language in Spanish-English code-switching and how this is related to the structure of mixed nominal constructions.


  • Welsh
  • Code-switching
  • Bilingualism
  • Spanish

Key Publications

Deuchar, M., Davies, P. & Donnelly, K. (forthcoming).  Building and Using the Siarad Corpus: Bilingual Conversations in Welsh and English.  Amsterdam: John Benjamins.

Wilson, C. & Deuchar, M. (2017)  Extralinguistic factors influencing the pronunciation of English by Welsh-English bilinguals. In Lauchlan, F. & Parafita Couto, M. (eds) Bilingualism and Minority Languages in Europe.  Newcastle upon Tyne: Cambridge Scholars Publishing, pp. 48-69.

Parafita Couto, M., Boutonnet, B., Hoshino, N., Davies, P., Deuchar, M. & Thierry, G. (2017).  Testing alternative theoretical accounts of code-switching using event-related potentials: a pilot study on Welsh-English.  In Lauchlan, F. & Parafita Couto, M. (eds) Bilingualism and Minority Languages in Europe.  Newcastle upon Tyne: Cambridge Scholars Publishing, pp. 240-254.

Deuchar, M. (2016)  Introduction: Cross-language effects in bilingual production and comprehension: some novel findings.  Bilingualism, Language and Cognition, 19(4), F1-F2. doi:10.1071/S136672891600050X.

Deuchar, M. & Biberauer, T. (2016).  Doubling: an error or an illusion?   Bilingualism, Language and Cognition 19(5), 881-882. doi:10.1017/S1366728916000043.

Deuchar, M., Donnelly, K. & Piercy, C. (2016) “Mae pobl monolingual yn minority: Factors favouring the production of code-switching by Welsh-English bilingual speakers.  In Durham, M. and Morris, J. (eds)  Sociolinguistics in Wales.  Basingstoke: Palgrave MacMillan, pp. 209-240.

Deuchar, M. & Stammers, J.R. (2016)  English-origin verbs in Welsh: Adjudicating between two theoretical approaches.  Languages 2016, 1 (1), doi 10.3390/languages1010007.

Deuchar, M., Davies, P. Herring, J.R., Parafita Couto, M. & Carter, D. (2014) Building bilingual corpora: Welsh-English, Spanish-English and Spanish-Welsh. In E. M.Thomas and I. Mennen (eds) Advances in the Study of Bilingualism. Bristol: Multilingual Matters, 93-110.

Stammers, J. and Deuchar, M. (2012) Testing the nonce borrowing hypothesis: counter-evidence from English-origin verbs in Welsh. Bilingualism: Language and Cognition 15:3, 630-643.

Carter, D., Deuchar, M., Davies, P., Parafita Couto, M. (2011). A systematic comparison of factors affecting the choice of matrix language in three bilingual communities. Journal of Language Contact 4: 1-31.

Herring, J., Deuchar, M. Parafita Couto, M.C. & Moro Quintanilla, M. (2010), ‘‘When I went to Canada, I saw the madre’: evaluating two theories’ predictions about codeswitching between determiners and nouns using Spanish-English and Welsh-English bilingual corpora’, International Journal of Bilingual Education and Bilingualism 13:5, 553-573.