using language!

Remember that old up-tight sexual innuendo comedy whose name I have mercifully forgotten but involved references to 'Percy filth' and 'using language'?  In that, bad language was anything remotely sexual....imagine that in a modern comedy!  

The official language of Zambia is English, chosen at Independence to avoid the tribal clashes that could follow the choice of one of the seven main Zambian languages as the national one.  English is the language of government, law, business, journalism, education past the first grades of school ; anything that requires a Zambia-wide or international response.  
On previous occasions when I worked in Zambia I was based in a college where English was an important part of the skills I was teaching.  Staff were from different countries and parts of Zambia so communication was in English and it was easy to believe that it was actually the national language.

The local language in the Eastern Province of Zambia and Lusaka, the capital city, is Nyanja, closely related to Chewa, spoken in other African countries including Malawi.
Being trained professionals, the Zambian staff should have a reasonable grasp of their national tongue and most of them do, to varying levels of competence but are, of course, more comfortable speaking in Nyanja. 

This effectively enables them to form a group closed to the bazungu (plural of mazungu, a Bantu word for white person, meaning literally 'confused person wandering about')  
When a conversation resolutely stays in Nyanja though I'm sitting apparently in the group or switches when I enter a room, I could be forgiven for feeling rejected from this little community though the truth is more likely a feeling of privacy, a family thing.  Difficult to feel part of this community as the language divide keeps us all in our proper  places.

I wonder when I've used language to exclude or keep at arm's length?  I feel sure I have: jargon, in-language, family jokes, literary or cultural allusions can be horribly effective in excluding.  My experience of exclusion here has increased my awareness of how I treat others.
I shall long remember the sudden burst of laughter in a group to which I can only smile pleasantly, pleased at their amusement and hoping I'm not the cause of their good humour.