The current thesis is based on four individual studies which aim to account for the expression of motion events (ME) in Spanish and Swedish as first languages (L1), in Swedish as a second language (L2), and in Spanish as a heritage language (SHL). The data, resulting from audio-recordings of different sorts of stimuli, have been analyzed with special focus on (1) the most common structures used for referring to various types of ME, (2) the types and amount of information provided by the participants, in particular as regards the semantic components Path, Manner and Ground, and (3) grammatical aspect and types of syntactic structures resorted to, including the correlation between the two latter factors and speakers’ discursive preferences.

     Study 1 sets out to explore how Spanish and Swedish native speakers convey information about motion. The results show that the Swedish L1 speakers produced a wider range of descriptions concerning Manner and Path than the Spanish L1 speakers; furthermore, both groups delivered detailed Ground descriptions, although the Swedish native speakers expressed final destinations (endpoints) of ME to a greater extent.

     Study 2 aims to investigate to what extent Swedish L1 patterns for motion encoding are still at play in the acquisition of Spanish L2 even at advanced stages of L2 acquisition. The results show that the learner group used a larger amount of Path particles and Ground adjuncts (in particular those referring to endpoints) than did the Spanish natives; this finding supports the claim that L2 learners rely on the lexicalization patterns of their L1 when describing ME in an L2. As for Manner, the L2 speakers were found to express this component mainly outside the verb, and to deliver more information about Manner than the Spanish natives.

     Study 3 addresses the construal of ME in Swedish speakers of L2 Spanish, in particular concerning the encoding of motion endpoints and Manner of motion. The results show that the Swedish learners of Spanish exhibited the same, high frequencies of endpoint marking as did their monolingual Swedish peers, thus deviating from the Spanish native pattern. Moreover, the L2 speakers used the same amount of Manner verbs as did the Spanish natives but tended consistently to provide additional Manner information in periphrastic constructions.

     Finally, Study 4 sets out to analyze the ways in which L1 Spanish/L2 Swedish early and late bilinguals express ME in SHL. The aim is to show in which ways and to what extent the typological patterns for motion encoding in the L2 may impact on motion encoding in the L1 with regard to three parameters: (1) age of onset (AO) of the acquisition of L2, (2) length of residence (LoR) in the L2 environment and (3) contact level with the L1 (CL). The focus data, consisting of oral re-tellings produced by the bilinguals, were compared to analogous data produced by two control groups (native speakers of Spanish and Swedish) in order to analyze conflation patterns regarding Manner, Path and Ground information. The analysis points to the conclusion that both the individuals’ AO of L2 acquisition and their LoR in the L2 environment have affected their L1 conceptualization patterns while their CL plays a subordinate role.

     In summary, the findings lend support to the idea that the habitual conceptualization of events in the L1 influences L2 acquisition; conversely, the conceptual patterns of the L2 have an impact on L1 usage in bilinguals, especially in combination with an early AO and a long LoR.