De Houwer's research engages several sub-fields of linguistics, including developmental psycholinguistics, contact linguistics, sociolinguistics, and second language acquisition. She is well-recognized for her wide-ranging research on bilingual children's language development, and has directed large longitudinal research projects on English-Dutch, Dutch-French, English-German, and German-Polish bilingual children. Her research has been supported by the Belgian National Science Foundation, the National Institutes of Health in the US, the Flemish National Science Foundation, the Special Research Fund of the University of Antwerp, the University of Erfurt, and the Harmonious Bilingualism Network.
