The real question when preparing students for proficiency exams is how to bridge the gap between their actual level and their target level.

Often enough, students need test results that are beyond their current level of language proficiency. A B2 learner – sometimes even B1 – needs a C1 score (overall Band 7) on their IELTS test in order to be accepted into a course or immigrate.
Looking at CEFR levels (B1, B2, C1), it might not seem like the daunting task that it is. Moving up levels is not a straightforward easy ride.
As described in Kolb (1984), the experiential learning cycle consists of four stages: doing, reflecting, thinking and re-doing. Experimenting with language means making mistakes in the process of making it make sense.
It is unlikely that a short test preparation course is going to take a learner from B1 to C1. Picture this: two 90-minute classes per week for seven weeks amount only to a 21-hour course. A 24-hour course might translate into eight weeks at the same pace.
Oftentimes, as teachers, we find ourselves torn between the belief that anyone can learn and develop, and the cold reality of reasonable timeframes. To put it simply, it is possible to move from level B1 to C1: this is what learning means. But it takes time. Generally speaking, a four-week window is not enough.
Studies suggest that it takes somewhere between 100 and 200 hours to move from one CEFR level to another. This time may increase the higher the level. So one might move from A1 to A2 in about 100 hours. But it might take them 150 hours to move from A2 to B1, for example. In terms of the IELTS test, it might take as much as three months to move up half a band.
Now, the good news is that those hours of learning don’t refer only to instruction hours. They include self-directed study as well. This means homework, but also watching movies in English, listening to music in English, reading books, articles, signs, labels, etc.
Time is relative. But the work you put into learning is not.
Useful links and reference:
How long does it take to learn a foreign language? (January, 2018) Cambridge University Press. https://www.cambridge.org/elt/blog/wp-content/uploads/2018/10/How-long-does-it-take-to-learn-a-foreign-language.pdf
Kolb, D.A. (1984). Experiential learning: Experience as the source of learning and development. Prentice-Hall.
