This paper presents the development stages of an NLP device to be used to improve students’ skills in French academic writing. Among various relevant difficulties, we focus on coordinating constructions that include or not ellipsis. We develop a tool to detect errors automatically in coordinated sentences from a corpus composed of erroneous and correct sentences. We use a deep learning approach based on the French CamemBERT model. To find the best learning environment for the classification task, we show the results obtained from training and testing datasets with different proportions of erroneous and correct sentences.