Many students choose to follow a language course abroad. Often with better results than a language course in the Netherlands because there is ample opportunity to practice the language.
The range of courses is large, so it is advisable to take your time and explore your options. Most language courses are easy to find on the internet. French, Spanish and English is offered almost everywhere, as well as German, Portuguese and Italian. Do you want to follow a language that is only offered outside Europe, it will take more time. Think carefully about the available time (how long will you be gone?), the level of the program (Beginner or advanced?) and the available budget.
The Global Exchange Programme also offers UvA students the opportunity to follow a language course. You can follow a Hebrew language course at Hebrew University of Jerusalem for a month, take Mandarin language courses for a semester or year at Peking University and Xiamen University, and take Japanese language courses for a semester or year at Hiroshima University, Waseda University and Keio University.