Why transfer is a key aspect of language use and processing in bilinguals and L2-users

Bilinguals and L2-learners are different from monolinguals not only because they know more than one language or can switch between languages, but also because they constantly need to juggle their languages: it has been proposed by some that both languages are active and available even when only one of them is being used (Bialystok, 2008; Dijkstra, Grainger, & Van Heuven, 1999; Kroll, Bobb, & Wodniecka, 2006). In situations where only one language can be used, bilinguals have to select words from the language which is needed for that particular interaction, while inhibiting (or deactivating) words from the other language. According to Bialystok (2008, p. 4), the need to control attention to the target language in a context in which the other language remains active is the single feature that makes bilinguals unique. This process of attentional control is, however, not water-tight. Bilinguals sometimes need to activate one language for a few minutes or even seconds and another one in the next few moments. The linguistic consequences of this incessant juggling act are that bilinguals and L2-learners cannot keep their languages completely separate at all times, and features of the deactivated language regularly appear in the language the speaker intended to use. In the literature, these features are often referred to as interference, transfer or cross-linguistic influence, and their existence is well documented. In the past these phenomena have often been seen in a negative light as deviations from monolingual norms, to be avoided whenever possible (see Jarvis & Pavlenko, 2008, for an overview of such views). Even today, according to Ortega (2010), monolingual biases continue to be built into research, e.g. in the field of second language acquisition, and she therefore calls for a 'bilingual turn' in SLA. If we want to understand bilinguals and L2-learners as unique speaker-hearers (Grosjean, 1985), we need to abandon the monolingual view of bilinguals and L2-learners, and stop considering bilinguals or L2-learners as failed monolinguals who have only partial knowledge of two separate language systems. Under a holistic view of bilingualism, first proposed by Grosjean, monolinguals are no longer seen as the norm, and the separation of two language systems is not considered the ideal state of affairs for bilinguals. Instead, the psychological and linguistic consequences of the coexistence of knowledge of the L1 and the L2 in the bilingual's mind - which Cook (2008) refers to as multicompetence - become the focus of research which aims at discovering what it means to be bilingual. In this approach, studying transfer should be a first priority, because it provides the key evidence that bilinguals process language differently: the existence of transfer can provide crucial insight into the activation of languages and into the functioning of attention control in the bilingual mind. In some cases, contact between the languages in the bilingual can lead to the emergence of unique, hybrid features that exist in neither of the two source languages (see also Ng and De Leeuw, Mennen, & Scobbie, this issue). In the field of SLA, the role of transfer is still controversial, even though all researchers assume transfer to play a role in L2 acquisition. As is well known, Lado (1957, p. 11) strongly believes the role of the L1 to be crucial. The author points out that the fundamental assumption behind his work is that:. individuals tend to transfer the forms and meanings, and the distribution of forms and meanings of their native language and culture to the foreign language and culture - both productively when attempting to speak the language and to act in the culture, and receptively when attempting to grasp and understand the language and the culture as practiced by natives.Many assumptions behind Lado's theory, which laid the foundations for the Contrastive Analysis Hypothesis, are no longer valid, however. …