The aim of this article is to give an overview of researches about the acquisition of /E/ verb endings in French as a first language. The spelling of this suffixal inflection is a major difficulty of French orthography, because many alternative spellings are available. For example, the single phonological form /parle/ can be spelled parlé, parlée, parlés, parlées, parler, parlez, parlait, parlais, parlaient, all of which are frequently used. This spelling difficulty is sustainable and generates strategies from writers who seem to accommodate opposite constraints originating in different linguistic levels of the French writing system. The main findings of a study carried out in school with 621 students from 8- to 14 year-old are presented: the early competition between -é and -er inflections, the over-regularization of the agreement with the subject and finally the interaction between the selection of the morphonogram <é> and the overregularization of the agreement with the subject. Ultimately, the data collected show a very long and costly acquisition of the spelling skill that confirms that French writing system is one of the most difficult to master.