Nowadays, in the field of foreign language (FL) teaching, it is understood that a good user of an FL should develop a group of competences such as grammatical, sociolinguistic, discoursive and strategic competences. The need to consider all of them derives from the fact that the success in a real intercultural communication cannot be assured through linguistic knowledge only (Meyer, 2002). This thesis investigates how an unfavourable opinion can be expressed and also which linguistic elements are used and in which contexts this kind of opinion is given. Our aim, thus, is to propose a model of table that provides an understanding of the strategies used in the act of stating an unfavourable opinion. The concepts from systemic functional Grammar related to the context, as well as those of Pragmatics, were paramount to this research. The data - gathered by means of a Discourse completion test - allowed us to identify four categories that classify the ways of giving an unfavourable opinion, namely: 1. direct unfavourable opinion; 2. indirect unfavourable opinion; 3. false positive opinion; 4. absence of opinion. Furthermore, peripheral formulations were identified. Coexisting with the categories listed above, they aim at diminishing the impact of an unfavourable opinion and preserving the interlocutors´ face. The research showed that - in the context of foreign language teaching - the knowledge of the different acts of speaking is necessary, including the act of stating an unfavourable opinion, so that proper communication can be established in real-life situations.