My friend told me yesterday that her brother learned Esperanto as a school subject in Britain (Maidenhead, Berkshire, I think) in the 1960s when most of the rest of us were learning French. Esperanto is now taught in a few schools under the Springboard programme of the Esperanto Association of Britain (whose website is here).
I had another encounter with Esperanto today when reading the news headlines. There is a meeting of young Esperanto enthusiasts in Cardiff (BBC report here).
Esperanto is the most widely spoken invented, or planned, language in the world with about a million proficient speakers. Around ten times this number have studied the language at some stage and, although the vocabulary of the language looks European, there are speakers in just about every country. There are a few people for whom Esperanto is their native language.
When Esperanto was invented in the 1870s its creator, Ludwik Zamenhof, had lofty goals for it. Zamenhof was born in Bialystock, now in Poland, but then part of the Russian Empire. His family spoke Yiddish and Russian, but in the town there were other ethnic minorities speaking other languages, notably Polish and German. None of the ethnic groups got on with one another and Zamenhof believed that people would get on better if they spoke just one unifying language. It had to be a neutral language, rather than the language of those in power or of the dominant ethnic group, however.
There is evidence to suggest that learning Esperanto can be a good introduction to other foreign languages and can make the subsequent learning of French, Spanish etc easier. As one of the young people quoted in the BBC article says, he was able to learn Esperanto within a year, yet is still struggling with Welsh after eleven years. The language has regular grammar, few idioms and no difficult spelling issues, unlike English, and these factors help people learn more quickly.
For lots of information about Esperanto, see the website of the Esperanto Association of Britain.