This dissertation is a collection of three studies in which the main focus is on the role of Swedish L1 speakers’ background languages for the comprehension of written Italian at a lexical level. Italian is one of the foreign languages that Swedish pupils in upper secondary school can choose to study. Previous research on third language acquisition and the role of the background languages in the Swedish context has mainly concerned oral production. With the studies in this thesis we intend to contribute to research on third language acquisition regarding comprehension of Italian both as an L3 and an unknown language. The first study, written in Italian, is a licenciate thesis. It examines the lexical inferencing procedures of 12 upper secondary school pupils studying Italian as a beginner’s language when they are trying to translate as much as possible of an Italian text into Swedish by means of think-aloud protocols. The second study is an intercomprehension study, which means that the three participants did not have any knowledge of Italian. The role of the participants’ background languages when translating Italian text into Swedish was examined, with focus on which language(s) were mainly activated and used and the use of which language(s) led to the highest success rate. As in the first study, the method used was think-aloud protocols. The third study had 60 participants divided into three groups. Neither of the participants had any knowledge of Italian. One group translated, in writing, a short Italian text into L2 English, the second group into L3 Spanish and the third into L3 French. The results of the three studies indicate that all the languages that the participants know are to some extent activated and used for the comprehension of Italian. Furthermore, it appears that the language into which the participants were asked to translate had an impact on the activation of the background languages. If they were asked to translate into another foreign language instead of Swedish, Swedish was not activated and used to the same extent
