How long is it going to take me to speak English fluently?
I've virtually lost count how many times students can ask me this question. The problem is they usually ask not only teachers but administrative staff with whom they come into contact first and in whose information they trust and believe.
Then they come into the classroom and ask the teachers the same question. The answer is normally quite different. To be honest, though, there is no right answer for two main reasons.
First of all, it is hard to truly quantify a student can learn in the space of a year or two: most language schools prognosticate that at the end of X years, student A will be at level Y. And there are countless examples of students having taken the same course and are at very distinct language proficiency levels.
Second, learning a language is an ongoing process. That means even studying five or six years, there is always something you can and will learn, IF you are willing to do just that. There is no end road to the process, which is not necessarily a bad thing. Think of language learning as a journey with new and enjoyable paths along the way, not as a race course with a finishing line.
To end, some advice to students to keep motivation high and disillusionment quasi null:
1. Set realistic goals about what you want to learn
2. Constantly check what you have learned and understand what you can do with the language
3. Know your part in the process: the language school you choose is important, the teacher is fundamental, but you are what you learn.