A renewed interest in studying the neural basis of Language has emerged since a clear relationship between speaking and the brain tissue was established. This study is focused on the assessment of language functions in patients with a specific kind of brain tumour, a low-grade glioma (LGG). These patients, who are submitted to an awake brain surgery, are assessed pre-, post- and intra-surgery, while using Direct Electrical Stimulation (DES), so that the neurosurgeon can optimise the extent of the resection and avoid language deterioration. The Dutch Linguistic Intraoperative Protocol (DuLIP) was developed in the Netherlands, consisting of a test battery for evaluating Phonology, Semantics, Syntax and Articulation. Since in Portugal there is no validated instrument to serve this purpose, the DuLIP was adapted to European Portuguese (EP). The process included a cultural adaptation and the collection of normative data from the Portuguese population. The DuLIP-EP consists of a total of 18 tasks. The focus of the present Thesis is only Syntax and Naming skills. To culturally adapt DuLIP, some changes had to be introduced regarding image choice and words frequency. After applying the battery test to 144 participants, a statistical analysis was performed aiming to find differences in scores per task, regarding gender, age and education level (years of study). Related to Syntax, a relationship between active/passive voice sentences and accuracy rate was analysed, as well as the influence of education level on the capacity of processing these sentence types. Similar to the original study, significant differences were found considering age and years of study. Younger and highly educated participants performed better across all the tasks. No association was found regarding education level and performance on the task where active/passive voice sentences were presented. Future work aims to achieve an identical number of items per task, a wider sample collected in all regions of Portugal, in order to perform a larger number ...