When learning a language it helps if you can immerse yourself as much as possible in it. It also helps if you immerse yourself in the culture of the people who speak the language. One if the first things you learn might be the words to use to greet people, for example, but do you know whether to shake their hands, bow, kiss their cheeks, or do something else when you greet them? Do you know which topics of conversation are acceptable and which are best avoided? Do you know how close to stand to someone and how to take turns in conversation? These are all important parts of culture that differ from country to country, and even within countries. Some language text books touch on things like this, but few go into any depth.
There are books and websites that explain the cultures and etiquette of particular countries – I find the Culture Shock! series of books interesting and useful. You can also learn about culture, at least to some extent, by watching films and TV programmes, but the best way is probably to spend time in a country or region where your target language is spoken and to be observant, and to ask questions about any cultural practices that puzzle you.
You might end up adopting some of the cultural practices, even ones that seemed really strange at first. For example, after spending time in Japan I started taking off my outdoor shoes and putting on indoor ones when arriving home, and being prepared to do so elsewhere. This habit has become so ingrained that it feels somehow wrong to wear outdoor shoes inside.
Do you try to learn about culture as well as language? If so, how do you go about it?
Have you adopted any habits or customs from other cultures?