In today’s society, language learners often acquire multiple languages throughout the lifespan. The languages that have been previously learned can positively and negatively influence the acquisition of further languages, a phenomenon known as transfer. Transfer from the L1 into the L2 is something which is relatively well studied, but what happens when we acquire a third language? Will there be transfer from the L1, the L2 or both, and what role do explicit prescriptive instructions (e.g. in classrooms and textbooks) play? These are some of the questions that we will address during this seminar. We will discuss different theories on transfer effects in a third language and methods on how to test such hypotheses. We will focus on transfer effects from German and English into Dutch and look at how these three languages differ and what this means for language acquisition. During the course, you will learn about second and third language acquisition and contrastive linguistics. We will look at what scientific studies have to say about acquiring multiple languages and what kind of advantages it can bring on a general cognitive and linguistics level. You will also learn about psycholinguistic methods and how to set up your own questionnaires and experiments. As a final assignment, you will carry out your own research project which we will develop through the course of the semester and that will be written up in the form of a paper. There is also the possibility of engaging in ongoing research projects.