How long does it take to learn a language?

Learning a language is more complicated than most people realize.  The sounds of the language, the grammar and the vocabulary must be learnt and also practiced in real conversation.  We have seen our beginning students reach the advanced level in 100 - 150 hours of class but they will continue to improve as they use the language in future years.  Our 16-hour course is a convenient step and each student decides when his/her goal has been reached.