Croatian is the most important subject in learning and teaching. All communication is carried out in the mother tongue. Along with parents, it is teachers who play the most important role in encouraging communication among students. Education is still mostly based on the traditional way of teaching, so it is necessary to turn teaching to modern methods. Teachers must use methods that will encourage students to develop their potential. Through various steps, the teacher should awaken the creativity of students, encourage them to communicate and to shape and express their own opinions. By developing communication competencies, students are taught how to use language skills in real communication. For this reason, students need to be exposed to speaking situations in order to apply the learned knowledge. This is the basis for expressing one's own opinion in order to develop critical thinking with the encouragement of the teacher. It involves discovering and solving problems through critical thinking, confronting other people's opinions in order to make a decision. The goal is for the student to express his / her opinion in a safe environment without hesitation and, more importantly, to substantiate his / her opinion with facts. Thesis offers four proposals that can be used in the practical implementation of the first to fourth grade in all subject areas. Thesis goal is to point out the importance of teachers in shaping critical thinking in students from first to fourth grade and to show ways how to incorporate different forms of discussion into Croatian language classes. It is on these foundations that students will perfect various forms of oral and written discussion through the rest of primary and secondary education.