Very interesting question there. I think if generation stage has been achieved by a language learner learning of, other languages becomes easy. However, similarity in language does speed up learning. One more thing if a learner has reached a step farther that is started leading his own learning will facilitate him to comfortably learn any other language. I hope it helps! You may like to see my postings for quality aspects in language learning. Thanks!

Thank you for your responses.

I understand that there are are issues with any form of terminology and categorization, particularly with regards to language acquisition. I also, however, think that if there are processing differences in so-called L2 and L3 learning, then a lot of research has overlooked it. When gathering L2 English participants, not all research asks for a full language background, in which case English may be an L2 in the sense that it is the language learned sequentially after the L1(s) but it does not necessarily imply that the learner only has one L1. I would think this may have implications for research, especially using reaction time.

I will need to look into it further, but in the meantime, thank you.

I think that this terminological issue can be fairly straightforward (though the implications regarding learning and processing as mentioned by other respondents is quite interesting).....to directly answer you, regardless of whether the learning is simultaneous or sequential (to use that categorization), once the stage of recognized separation of the two languages occur, then the two are recognized as separate languages during use so the next learned would be L#.

Mizuki Moriyasu

·         Traditionally, the theory of Second Language Acquisition, which has drawn heavily from cognitive-based paradigm of language processing, only considers First Language and Second Language Acquisition as the only possibilities. The language specific cognitive mechanism, a construct of the innate language potential that all humans possess, but which is affected by first language acquisition and ageing, brings about this broad divide. The acquisition of a third, fourth or fifth language of encounter is still considered as Second Language Acquisition because the Language Acquisition Device   parameter settings have already been fixed, more or less, permanently on the basis of the structure of the first Language. Any language of encounter after the first—native, mother-tongue—therefore is regarded as a second language.

·         However, on the basis of the logic of Universal Grammar, and the Principles and Parameters approach, one might consider ‘learn-ability’ in a logical manner, and possibly think of what happens when the LAD encounters multilingual data. In this scenario, the parameters that relate to a given UG principle, and their relative ‘marked-unmarked’ dialectic, and how they are manifest in the first language, a second, third, fourth or even fifth language, may be of issue in acquisition.  There are studies that have been done regarding this, and yet others are ongoing!  

I agree with Stephen that there is not an all-or-nothing line between simultaneous and sequential bilinguals. The most agreed-upon age of acquisition in defining and separating the two (i.e. the age of 3) is rather convenient. The fact is even for simultaneous bilinguals growing in an immersive context whould show dominance in one of the two L1s. If there is a case of balanced simultaneous bilingual, then the third language should be more appropriately referred to as the L2. However, many studies on the so-called L3 acquisition (e.g. Rothman and his colleagues) involves sequential bilinguals learning a third language.

Thank you for your responses.

I also agree that there the difference between simultaneous and sequential is not clear-cut. For that matter, a great many things regarding languages are not clear-cut, which I believe to be the fundamental flaw in attempting empirical research in applied linguistics. Nonetheless, I think research is necessary, but such blurred distinctions need to be taken into account.

In response to Yakobo Mutiti, I believe Vivian Cook suggested that taking a multicompetence approach, the input as well as resulting grammar knowledge would pass 'bilingually' through the LAD, allowing for a single bilingual grammar. However, as Chomsky's monolingual-centered theories and Cook's adaptations are still very opaque, I would like to return to my original question of how processing may be different.

In a sense, my question may be: is bilingualism cognitively the same for everyone, thus making acquisition of a third language the same across different 'types' of bilinguals?