Multilingual speakers’ linguistic practices are typically investigated via self-report measures, often relying on subjective memory recall. This article examines the potential of an interdisciplinary methodology which would allow us to examine the experiences of multilingual speakers as they are played out in real time and space through a combination of GPS monitoring, the use of Electronically Activated Recorder (EAR) and map-based ethnographic interviews. GPS and EAR offer promising opportunities to investigate the spatial dynamics of multilingual practices as well as acquiring a new language and its subsequent use. Despite frequent applications in adjacent fields such as human geography, urban analytics, sociology and psychology, the use of these methods in applied linguistics is still relatively scarce. In this article we examine the potential benefits as well as limitations of using automated processes for observing language human behaviour such as those provided by GPS and EAR technologies. It addresses timely ethical questions in the age of AI development and solutions to devise privacy-preserving tools when using GPS and EAR technologies. It looks at how the potential of these technologies can be optimised when combined with qualitative and ethnographic approaches, providing rich accounts of the human stories behind these behaviours. Our article looks at how, in combination, these various methodologies can provide a more nuanced understanding of the spatial dynamics of multilingual speakers in cities.