korespondi

This is the verb the movement ran on for its first century. Zamenhof started printing an Adresaro in 1889 - a list of everyone known to have learned the language, with their addresses, so that strangers could write to each other. Correspondence services matching pen-pals across borders ran for decades after that, with addresses printed in the yearbooks. Thousands of people became fluent in Esperanto without ever hearing it spoken, because korespondado was the language. The letter writing and register article is where the etiquette lives, and it is unusually settled etiquette for a language with so few native speakers, precisely because letters were the main event.

Our story La festivalo ends on the same note, and deliberately: two friends part at a railway carriage, nobody promises anything, and the letters go anyway.

The derived words, all in circulation.

• korespondado - correspondence as an ongoing activity, the word in the yearbooks
• korespondanto - a correspondent, the person at the other end
• korespondaĵo - a piece of correspondence, the physical letter
• korespondamiko - a pen-pal, and yes, the compound is that transparent

The construction. You korespondas kun somebody, not al them, because the letters go both ways: kun is the whole point of the word. It is intransitive, so there is no accusative object waiting for you.

One thing it does not mean. English correspond also covers to match up, as in "these figures do not correspond". Esperanto keeps that separate: kongrui is to tally or agree, and respondi al or konformi al will also do it. Korespondi is about post, and the older dictionaries that allow the matching sense mark it as rare. Say what you mean and the reader will not have to guess.