Difficulties in learning a second language.

What are the difficulties in learning a second language? Clearly one of the main difficulties is that usually the learner does not live in an environment where the second language is commonly spoken. |The language may be used in special language may be used in special language classes or even as a medium of instruction in school, but generally only a fairly small proportion of the learner's time is spent in using it.Another difficulty is that of 'interference' between the learner's mother tongue and the second language. Interference is perhaps most noticeable in pronunciation, but also affects the learner's understanding so another language then is clearly not easy. It requires interest, persistence the confidence to make mistake sand the determination to correct them.