There are many possible problems we have when we learn languages.
First, sometimes people feel shy when they speak a foreign language and they start using strange voices. When someone does not understand us, we may start speaking more loudly, but it does not help when it is a language problem!
Second, when people learn languages from books, they may know the grammar and vocabulary quite well, but not be able to pronounce words correctly. Then there may be many misunderstandings(误解). Sometimes someone says something very nice and polite, but because their pronunciation is wrong, it causes trouble—people hear something very naughty and everyone's face goes red!
Third, what else can go wrong? Some learners may be good at speaking. Maybe you can ask in French, "How do I get to the station?" But if your listening is not good, it won't help you when the Frenchman gives you a long, fast answer, because you can't understand what he says.
Finally, you also need to be sure you speak the correct form(形式）of a language. For example, Japanese men and women speak a little differently.
