Although the Basque Education Law mentions that students must finish secondary compulsory education at B2 Basque level and their undergraduate studies at the C1 level, there are no objective tests or tools that can discriminate between these levels. This work presents the first rule-based method to grade written Basque learner texts. We adapt the adult Basque learner curriculum based on the CEFR to create a rule-based grammar for Basque. This paper summarises the results obtained in different classification tasks by combining information formalised through CG3 and different machine learning algorithms used in text classification. Besides, we perform a manual evaluation of the grammar. Finally, we discuss the informa- tiveness of these rules and some ways to further improve assisted text grading and combine rule-based approaches with other approaches based on readability and complexity measures.