We hear all the time that English is the lingua franca of a globalised world, the common language, the common denominator, the fallback communications conduit.

World English Language Day, which was on 23 April, is a UN initiative that celebrates the language and promotes multiculturalism. The other five official UN languages – Arabic, Chinese, French, Russian and Spanish – each have their own official day.

What I particularly like to celebrate on World English Day is not one standard form of the language, but its huge diversity across the planet. English has hundreds of dialects of rich vocabulary with nuanced grammars, often reflecting speakers' other languages, and an extraordinary variation in accents in places only short distances apart. The language that lets people of different tongues get together for business and pleasure is as gloriously diverse as its speakers.

This resonates with me, working in an agency that produces communications materials for diverse audiences. While it's true that there may be a lingua franca that can reach them all at one level, a good internal communications campaign should be customisable locally, and should give people a voice – in their own language or dialect.