We investigated the effectiveness of two different teaching methods based on two different theoretical views of how languages are learned in oral proficiency after three years of L2 French instruction. The first method is commonly used in the Netherlands and is in line with structure-based (SB) principles, viewing language as a set of grammar rules that need to be explained to achieve accuracy, usually in the L1. The second method aligns with dynamic-usage-based (DUB) principles in that language is viewed as a set of conventionalized routines that are learned through frequent exposure and the L2 is spoken exclusively in class. In a large study (Rousse-Malpat et al., 2019), the DUB method proved more effective, but the effects of method and L2 exposure could not be separated as the amount of L2 exposure is a crucial difference between the methods. However, one SB teacher spoke French almost exclusively, comparable to what happens in a DUB classroom. In this study, we compared this SB group with a DUB group matching in scholastic aptitude. The free oral L2 French production of 41 Dutch participants was measured in terms of holistic and analytical scores. The DUB method was more effective in terms of general proficiency, fluency, grammatical complexity, accuracy of the present tense, and overall L2 use. Our findings suggest that a teaching method in line with DUB principles is more beneficial in achieving overall oral proficiency and explicit grammar is not needed to achieve accuracy.