Children can acquire more than one native language — for example, Portuguese as a family language and German as the community language in Germany. But what happens to these childhood languages after moving to Portugal? Can Portuguese further develop? And under what conditions are competencies in German maintained? These questions are the focus of Prof. Esther Rinke (Goethe University), Aldona Sopata (Adam Mickiewicz University Poznań), and Cristina Flores (University of Minho Braga) in their large-scale project, which has now been awarded a Synergy Grant by the European Research Council. They have secured a total of 8.8 million euros for the initiative. The project is planned for six years and aligns with the European Union's goal of promoting linguistic diversity. To date, the question of how languages acquired in childhood by multilingual individuals change when the linguistic environment changes has not been comprehensively researched.
The project, titled "Navigating the Pathways of Nativeness: Attrition and Reinforcement of Childhood Languages in Contexts of Return Migration" (NAVAR), examines individuals who acquired Polish or Portuguese as a heritage language and German as a community language in early childhood. If they return to the country of their heritage language—Poland or Portugal—later in life, the everyday presence of the two languages shifts: Polish or Portuguese then becomes the community language, while German recedes into the background.
In NAVAR, researchers will investigate how the two childhood languages develop under these altered conditions. Can linguistic knowledge in Portuguese or Polish further develop through increased usage? Which areas of German are particularly affected by language loss, and which remain more stable? Furthermore, which cognitive factors and personal attitudes toward the two languages counteract the loss of German? Data will be collected from a total of 1,000 multilingual speakers. Linguistic experiments will be supplemented by interviews regarding migration history, and cognitive abilities will also be integrated into the study.
The language pairs German/Portuguese and German/Polish also allow for the investigation of which properties of the heritage language favor the preservation of German. If the two languages share similarities—for example, the existence of the article in both German and Portuguese—is competence in that specific area more likely to be preserved in German? Since Portuguese and Polish share different linguistic phenomena with German, these two languages are particularly suitable for the study. Ultimately, however, it is not about these three specific languages, Rinke explains: "In the end, our project aims at universal findings regarding language loss and language development in adulthood. We hope to establish linguistic predictions about which areas of language remain flexible in adulthood and which do not." Until now, reliable data on this has been lacking. "It would be wonderful if our project marked the beginning of a new field of research," says Rinke. While it is linguistic basic research, the project can help derive strategies for how childhood languages can be preserved and strengthened.
"The ERC Synergy Grant is a very special distinction for our university," says Prof. Bernhard Brüne, Vice President for Research at Goethe University. "This is the first time a research personality at Goethe University has succeeded in securing this prestigious funding. When you consider that the success rate was only five percent, the approval is all the more gratifying," Brüne continued. More than 950 project applications from all scientific fields were submitted; NAVAR is one of a total of 48 approved projects.
The ERC Synergy Grant funds research projects that can only be carried out through the collaboration of several scientists. Two to four Principal Investigators (PIs) jointly apply for up to 10 million euros over six years. The selection is primarily based on the excellence of the project and the synergistic effect between the participants. The three scientists involved in NAVAR are equal partners, with Goethe University serving as the coordinating institution. The official start is expected in May 2027; the project provides for a total of 13 doctoral and postdoc positions, as well as three positions for project coordination.

To the ERC press release: https://erc.europa.eu/news-events/news/synergy-grants-2026-examples-projects

Images available for download at: https://www.uni-frankfurt.de/190742747
Captions:
Image 1: Linguistics Professor Esther Rinke has secured an ERC Synergy Grant together with two other scientists. (Photo: Alexandra Lowles)
Image 2: Researching together how childhood languages develop in adulthood: Aldona Sopata (left), Esther Rinke, and Cristina Flores. (Photo: Alexandra Lowles)



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