There are students who have been studying English for years, and always end up in the same place, not advancing to a higher level. Some take international examinations several times with no success. The best thing an English learner can do is not to give up. If a student feels he has reached a plateau, quitting will probably mean forgetting and losing most of what had been learned. Quitting is not an option. It is important to stick to it until reaching a specific a goal, or at the very least redefine a goal that may be a little too unrealistic.