Visiting Americans (and Britons) are often quite surprised by and jealous of the multilingualism of continental Europe. People in small European countries rightfully pride themselves on their language knowledge. When you can drive to the nearest border within minutes, it can be quite useful to know your tongues. There seems to be a loose rule – the smaller the country, the more languages people know. The most extreme example is perhaps that of Luxembourg, where in order to become a bus driver one must be fluent in 4 languages.
An unfortunate side effect of the proficiency in languages, is that some people become linguistically-arrogant, thinking they master a language (usually English) while they are far from perfect in it. The people most prone to this linguistic arrogance are the Dutch, who actually know English quite well, but not as well as they sometimes think. The result is called Dunglish. A professor greeting his class by saying “I hate you all very welcome” is funny, albeit awkward. An info plaque in a museum telling you about something that has happened “in the mean time” get you stuck for a couple of minutes wondering whether it was an evil or an average time. But a prime-minister proclaiming his people to be “a nation of undertakers” its downright embarrassing. Unless he’s Khrushchev in which case he’s creepy.
The devil is in the details. Sure, it (usually) doesn’t kill you when a signpost is misspelled. But when you’re organizing a major international event, like today’s Rotterdam Marathon, and you’re making an effort to communicate to the foreign visitors, why don’t you make the extra step and have all your communications checked by someone who is really-really good in English? Otherwise they will be stuck in your town long after the event, nailed to their place by the fear of becoming a motorized vehicle should they move.