I think most language learners have been in the situation where they realise that the textbook or dialogue they are learning from is not at all relevant to anything they would need to use in real life. Of course, there are some fantastically-written learning materials out there, but there are also the ones that try to teach obscure terms that most people would never need to know. I remember a lesson where my teacher taught us the translation for double income no kids families, as well as a term which means a mistress whose rich boss boyfriend pays to raise her bastard baby. I guess that says something about the culture, though!
So, what can we do about it? If you’re lucky enough to have a private tutor, you do have some control over what you learn. Tell your teacher you are interested in learning to say certain things, or have particular conversations. If you are in a class situation, you can do some study on your own.
One way to work out what’s relevant to you is to think about the interactions you have within a day or a week. Could you navigate the supermarket, hairdresser, library, subway in your target language? If not, great! You’ve just found some new learning material. Think about what conversations actually take place during your day, and try to translate them. Note down (or look up) any vocabulary and sentence patterns you still need and bring them up with your teacher in your next class. Once you’ve got a good translation of the conversation, you can take turns at playing each role.
Next time you’re at the hairdresser (or supermarket, etc), go through the conversations in your head to solidify the language knowledge. Or, go ahead and try it out loud (if you are in a position to, of course).