Groupe classes allow you to practice your speaking skills and listen to the language with other learners at a similar level, they often offer a more dynamic and interactive learning experience than private classes and you can participate in group discussions, role-plays, and other activities. They are also a good option because they are generally more affordable than private classes. On the other hand, private classes offer you comfort in terms of time and mobility but above all, they allow you to choose a particular focus on a section of the language that you might need for future work and gives you the whole attention of the teacher.