In recent years, the debate around the relationship between executive control and bilingual language proficiency has extended to the investigation of the role of the former in second language learning. The present study is based on data collected from 20 native and near-native adult speakers of English and investigated the relationship between the learning of Brocanto2, an artificial language with a complex morpho-syntax, and two measures of executive function - cognitive flexibility and inhibitory control. Although the result of the present study did not support the existence of a significant relationship between executive function and the acquisition of L2 morpho-syntax, they confirmed the role of vocabulary learning as a factor possibly driving the correlations between language learning and executive function found in previous studies