"Formal linguistics and bilingualism: the “two in one” paradox
and the psychological reality of lexical transparency"

Abstract: We would like to discuss two theoretical issues that have methodological implications and will
approach the two issues from a linguistic and a psycholinguistic perspective.
We would first like to address how 2L1 speakers compare to their respective L1 speakers.
This comparison has implications for representation, processing, and acquisition. From the point of
view of representation, the relevant question would be whether a bilingual is the addition of two
monolinguals (Grosjean, 1989). In the case of processing, it would be important to determine how
the bilingual and the monolingual child operationalize lexical access: does the bilingual child
access the lexicon of one language in the same way as the respective monolingual? When it
comes to acquisition, we would ask, on the one hand, whether both developmental stages are
comparable and, on the other, whether the divergence from their respective adult production and
comprehension is similar. In this respect, while overgeneralization patterns can be shared,
crosslinguistic influence can only occur in the case of the bilinguals. Given this, it could be the case
that for a given representation the difference is linked to crosslinguistic influence and we could, for
instance, address whether monolingual English is going to have less “foot-s” or “tooth-s” than
bilingual English, and, if so, why.
The second issue that we would like to discuss is the so-called psychological reality of the
different levels of language structure and usage (Sapir, 1933; Beeman 2012; Al Mubaideen, 2015).
For instance, is it the case that we use a productive rule to utter “dogs” (dog  dogs)? or do we
retrieve the plural “dogs” as a unit? On a different level, what is the representation of null
categories in the mind of the bilingual and the monolingual child and how are they processed and
acquired?
Taking as a point of departure the two axes “two-in-one” and “psychological reality”, the
main objective of this presentation is to revisit our research on 2L1 acquisition of child English-
Spanish and L1 acquisition of child English and child Spanish (Fernández Fuertes & Liceras, 2010;
Liceras, Fernández Fuertes & Alba de la Fuente, 2012; Liceras & Fernández Fuertes, 2019). The
specific topics that constitute our focus of attention are the following: (1) the acquisition
(production/omission) of sentential subjects; and (2) the acquisition (production/omission) of copula
verbs. In the case of both subjects and copulas, we have compared child bilingual and child
monolingual data, which speaks to the issue of “two in one”; and we have accounted for
crosslinguistic influence in terms of lexical transparency which can be considered an instantiation
of “psychological reality”.

AL MUBAIDEEN, A. (2015). The psychological reality of phrase structure rules. British Journal of
Humanities and Social Sciences 13(1), 189-194. BEEMAN, W. O. (20120. Linguistics and Anthropology.
In D. M. Gabbay et al. (eds.), Philosophy of Linguistics (pp. 531-551). North Holland FERNÁNDEZ
FUERTES, R. AND J.M. LICERAS. (2010). Copula omission in the English developing grammar of
English/Spanish bilingual children. International Journal of Bilingual Education and Bilingualism
13(5), 525-551. GROSJEAN, F. (1989). Neurolinguists, beware! The bilingual is not two monolinguals
in one person. Brain and Language 36, 3-15. LICERAS, J.M. AND R. FERNÁNDEZ FUERTES. (2019). Subject
omission/production in child bilingual English and child bilingual Spanish: the view from linguistic
theory. Probus 31(2). 245-278. LICERAS, J.M., R. FERNÁNDEZ FUERTES AND A. ALBA DE LA FUENTE. (2012).
Subject and copula omission in the English grammar of English-Spanish bilinguals: on the issue of
directionality of interlinguistic influence. First Language 32(1-2), 88-115. SAPIR, E. (1933). Language.
In Encyclopedia of the Social Sciences (pp. 155-169). Macmillan. SMITH, N. (1999). Psychological
reality. In Chomsky: Ideas and Ideals (pp. 93-135). Cambridge University Press.