bilingual children in Wales, while Thomas, Cantone, Davies and Shadrova,
also using behavioral data, examine crosslinguistic influences in the acquisi-
tion of gender and word order by two Welsh-German children. The contribu-
tions by Sanoudaki and Thierry and Hoshino and Thierry extend the study
of crosslinguistic influences to include electrophysiological recording tech-
niques (ERPs) in order to examine the neuro-cognitive substrates of grammar
processing and speech production, respectively, in bilingual Welsh-English
adults. ERP techniques, and other neuro-cognitive methods, are especially
powerful tools for the study of cross-linguistic effects in bilinguals because
they are capable of showing underlying interactions between languages in
bilinguals that may not be evident from behavioral data alone. Mayr, Jones,
and Mennen add to our understanding of cross-linguistic influences in bilin-
gual acquisition in a study of the phonological development of Welsh-
dominant and English-dominant bilingual children. de Leeuw’s chapter
examines the ultimate cross-linguistic effect of bilingualism; namely, attri-
tion of the first language (in phonology) as a result of acquisition of a second
language – in this case, in adult German-English bilinguals.
Code-switching, the co-occurrence of sounds, words and/or morphosyn-
tactic patterns from two languages in the same conversations or utterances,
is the most evident manifestation of the interactions between the two lan-
guages of bilinguals and, in fact, one of the first preoccupations of research-
ers in the field (e.g. Leopold, 1949; Genesee, 1989; Meisel, 1994; Vihman,
1998). It is examined in two contributions in this volume. Parafita and her
colleagues examine whether speaker-based variables or community-wide
characteristics can better account for code-switching patterns in the two
corpora – a Welsh-English corpora from Wales and a Spanish-English corpus
from Miami. Deuchar and her colleagues provide a detailed explication of
how to build bilingual corpora as part of their description of a study of bilin-
gual code-switching in groups of bilinguals learning three different language
combinations, including Welsh and English. The methodological emphasis in
these studies is how best to collect natural language samples to study this
widely-practised form of bilingual language usage. Collectively, the findings
from all ten studies in this volume explore and document the systematicity
of crosslinguistic interactions and, in so doing, serve to show that such inter-
actions are ‘... a perfectly normal phenomenon resulting from language contact’, to
quote from Mayr and his colleagues.
Going beyond linguistic, psycholinguistic, and neuro-cognitive perspec-
tives, Lewis and Andrews and Jones and Lewis examine bilingualism in edu-
cational contexts, specifically in higher education and in primary and
secondary education, respectively. At issue in these contributions is how
languages are used and can best be used in bilingual schools in Wales to
promote Welsh, a minority language, along with English, a majority lan-
guage that poses a constant threat to Welsh. While clearly practical in focus,
at the same time, these studies, and especially that by Jones and Lewis on
xiv Advances in the Study of Bilingualism