Bachelor Thesis from the year 2016 in the subject Sociology - Work, Profession, Education, Organisation, grade: 4.8, University of Colombo (UNICA), language: English, abstract: The purpose of this study is to illustrate some of the effects of negative emotional traits in the teaching performance of two English seven and eight grade teachers with forty students each in a public school in Suba, Bogotá. The work focused on three negative emotional traits (frustration, anxiety and lack of creativity) that are the core of a negative class environment. The research of Ferguson, Frost& Hall (2012) explores some of the physical effects such as increased blood pressure, anger, headaches, and some psychological effects such as anxiety, nervousness, tension, frustration and panic, that some teachers might experience when they are exposed to situations of high amount of stress. Furthermore, those effects can affect teacher performance when teaching classes. Two case studies described the situations that affect teachers' performance, how teachers reacted when experiencing those situations and what the outcomes are in the classroom environment. The main situations found during the study are related with students' behavior, students' attitude about class activities, school demands regarding class structure and the amount of English use during classes.