Beppe Severgnini, in his book Inglesi, is amazed by what he calls the ‘harmless ceremonies’ of British daily life. He describes a discovery made by an incredulous Italian friend of his that “in Britain you need four ‘thank yous’ to buy a bus ticket”. Severgnini comments:

Italians are amused by this ritual; when they have to pay for their tickets at home they normally do it with a grunt. Americans who normally carry out such transactions in dead silence are flabbergasted.

Of course this kind of ‘politeness shock’ works in reverse as well. And sometimes, the visitor returns home with a kind of linguistic infection: an Argentinian colleague who had spent several weeks on a course in Britain, returned to Buenos Aires, got into a taxi at the airport and told the driver – in Spanish – where she wanted to go – so far, so good – but after giving him her destination, she added por favor – whereupon the man swivelled round, smiling broadly, and said “Señora, if you ask me like that, I’ll take you to the ends of the earth!”
When we travel abroad, whether in reality or just in the virtual reality of the language classroom, we experience the same sense of dislocation – the more remote from us the other culture is, the more obvious this will be – in an African or Arab or Asian setting, we would be acutely and immediately aware of difference; but if the other culture appears on the surface to be similar to our own, the apparent similarity may be very deceptive, and it may take a long time before we realise the implications of people’s behaviour and the significance of the cultural sub-text.
H Douglas Brown (1980) describes the experience of culture shock as it refers to a person learning a second language in a second culture: Culture shock refers to phenomena ranging from mild irritability to deep psychological panic and crisis…. [It] is associated with feelings in the learner of estrangement, anger, hostility, indecision, frustration, unhappiness, sadness, loneliness, homesickness, and even physical illness. Clearly, feelings such as loneliness and homesickness apply specifically to the learner who is resident in the new culture, but the negative mindset that builds up, the feelings of bewilderment, disorientation and frustration, certainly remind me of how it sometimes felt when I started to struggle with foreign languages at school.
An early attempt to understand and categorise what happens to the intercultural traveller- learner was made by Robert Lado (1957). Lado suggests that apart from those (possibly rare) cultural behaviours that have the same form, the same meaning and the same distribution, where the cultural equivalent of 1:1, word-for-word translation is possible, there are three categories of difference: same form, different meaning; same meaning, different form and same form, same meaning, different distribution. The first – same form, different meaning – may be the most puzzling: something looks the same, but turns out to have a different significance. For example, I may assume that an Apothek in Germany or a farmacia in Italy is exactly the same as a British chemist’s, as it seems to serve the same purpose – on closer investigation, however, I may find that the range of goods on sale is rather different and the kind of advisory paramedical relationship I assume I can enter into with a British pharmacist may not be available. The second category – same meaning, different form – is less troublesome if you can find out what the appropriate form should be. For example, I may assume that it is polite to take a bottle of wine if I am invited to dinner anywhere in Europe, whereas I need to find out where wine would not do the trick at all and where the same function is performed by cake, flowers or ice cream. Lado’s last category – same form, same meaning, different distribution – is a subtler one and probably takes longer for the learner to identify and assimilate. For example, uttering a verbal greeting on entering a shop is an available behaviour for me, but it has rather limited distribution – ie in Britain I do not feel the social need to do it very often – so I may not appreciate the expectation that exists in many other cultures that this is something that a customer should always do.