Third Languages Acquisition (TLA): Educational Multilingualism at Early Ages

In an increasingly globalized world, learning foreign languages (FLs) is essential, particularly in education. Multilingualism is critical due to the multicultural and interconnected nature of societies, yet early third language acquisition (TLA) is not widely adopted in schools. This study investigates how the simultaneous learning of Spanish first language (L1), a second language (L2), and a third language (L3) impacts oral language (OL) development in L1 and whether prior L2 knowledge aids L3 acquisition. The study involved bilingual (L1 + L2) and trilingual (L1 + L2 + L3) learners. Data were collected using the Navarre Oral Language Test-Revised, which evaluates phonological, morphological–syntactic, lexical–semantic, and pragmatic competencies in oral communication. Findings revealed that trilingual learners showed better OL development in L1 compared to bilingual learners. Additionally, prior L2 knowledge facilitated L3 learning, highlighting the benefits of early trilingual education. The study demonstrates that early trilingual learning positively impacts OL development in L1. These results contribute significantly to research on TLA and the advancement of multilingual education.