It’s a misconception that some people are destined never to roll their ‘r’s. In countries with ‘r’ rolling languages, many people learn the skill in childhood. Spanish is an example of one such language. However, those yet to master the skill need only to practise. The key is to tuck your tongue behind your upper front teeth, resting the tip on the ‘alveolar ridge’ – the small, bony protuberance just behind the teeth. It’s also important to relax the tongue so that it vibrates as the air flows past.
Rolling an ‘r’ is strikingly similar to blowing a raspberry. In fact, some language experts suggest beginning training by blowing a raspberry while humming, or doing a lip trill while moving the tongue up. Be prepared for hours of practise, but perhaps not in the office, unless you have understanding colleagues!