The truth: there is no exact answer.
First, because every person is different: some will learn much faster than others, which has nothing to do with intelligence. But it’s a fact that for some people learning a language is easier than for others.
Second, because language learning is not linear: the higher your level, the slower the process. Getting from an A1 to an A2 level will be much faster than from a C1 to a C2, even if both are just one level.
Third, the time you need to invest also depends on your final goal. Do you need Spanish for travel? Or just for conversation with staff? Or do you need to negotiate important deals in Spanish?
And fourth, it depends also on many other variables such as age, motivation, time spent per week studying, knowledge of other languages and the student’s retention capacity. It’s important to mention that there is no link between intelligence and the ability to learn a language!
The afore-mentioned are some of the variables to take into account when deciding how much time you need to invest.
However, because of the intensity of the ANDERS LANGUAGES program, you can be sure there will be a significant improvement in a short time.