British council, is a UK cultural centre,like many other countries cultural centres found in tz,one of their duty is to promote british culture which incl their language. They found at samora aven,they are conducting two modules of learning engl language, first is engl practice (which incl engl for beginner,interm level and adv level),when you go there you they arrange an appointment with you in which you will meet an english lady for speaking session (in which you will be asked different unplanned engl qstns abt hobbies and life in general) from this discusn is where they may group you in suitable level as beginner,interm or advanced. Other module is TOEFL (test of engl as foreign lang), this is specifically for those who are preparing to join in university in countries which are using engl as teaching lang,they must be tested either physically or online and their scores must be shown at their cert. (below certain scores,you cant be enrolled).