Learning rate and success as a function of code-switching strategies in the input

Code-switching is a natural phenomenon in which a speaker alternates between two languages. Although code-switching could be a useful tool for foreign language learning (Bhatti et al., 2018; Macaro, 2005), it is unknown what types of code-switches are potentially most useful. To investigate this, we present an experiment in which we compare learning rate and success of learning vocabulary (nouns) and functional categories (determiners) from input containing two types of switches from English into a Swahili-based artificial language: inserting two adjacent words (e.g., Kiti ro is next to the book) or inserting two distant words (e.g., The kiti is next to book ro). Images help participants deduce word meaning. Recall accuracy over successive cycles is used to provide a measure of learning rate for nouns and determiners, allowing us to gauge the effect of code-switching on learning grammar and lexis independently. Data collection (n ≈ 40 per condition) is ongoing