When a foreign language interferes with your native language: The relationship between second-language acquisition and first-language attrition

My PhD project looks at how learning a second language after puberty may have effects on the way one speaks his or her own first language;what, in developmental linguistics, is known as first-language attrition. I am particularly interested in understanding whether first-language attrition affects different domains of linguistic competence to the same degree, and whether attrition goes hand in hand with second-language acquisition. To put it in other words: is the ability to remember words influenced more than that of forming grammatical sentences in your first language? But also, does second language learning affect the way you sound in your first language, too - in that your accent might get less native-like in your first language? Additionally, I am intrigued by the factors which, in turn, might mediate the degree of first-language attrition that one experiences - such as the type and quantity of input in the second language, the amount of time spent actively speaking the language, and the degree of proficiency reached in the second language. I ultimately aim to understand not only what, but also who gets 'attrited'- is it the most proficient second-language learners? Those who are immersed in a foreign-language environment? Or less proficient, classroom-based learners, too? In order to address these under-examined issues, I will be gathering data from different groups of language learners: in the UK, I will look at how learning Italian in a classroom compares to studying Italian abroad for a semester; similarly, in Italy, I will look at how learning English in a classroom compares to studying English abroad for a semester. I will then examine the effects that learning Italian has on English, and those of English learning on Italian. The language domains I will examine in both Italian and English are (1) lexical access (i.e. the ability to recall words); (2) the interface of syntax and pragmatics (i.e. the interpretation and production of structures which are constrained by contextual features - such as pronouns); and (3) prosody (i.e. sentence stress by placing accents on specific words). In my analysis, I will seek to understand whether these domains are similarly affected by attrition, whether immersion in the foreign-language environment plays a role in the occurrence of attrition, and whether there is a link between second-language proficiency and first-language attrition.My personal interest for this PhD topic stems from my very own background: when I was 15, I was awarded an AFS scholarship which allowed me to attend a high-school year in Nashville, Tennessee. When I returned to Italy, one year later, my parents and I were very much surprised whenever I could not remember words, or when the things I said in Italian did not make much sense. When I was introduced to the field of second-language acquisition and first-language attrition at University a few years later, it all became clear to me: I was - and still am to this day - experiencing attrition on my first language. However, there is still much to be done to understand precisely how first-language attrition works: my project hence addresses some of the gaps in our current knowledge of the phenomenon. Furthermore, I believe that a more thorough understanding of attrition and language learning in general will not only benefit me, but our increasingly bilingual and multilingual society as a whole.