The old adage that loose lips sink ships – or, at any rate, risk burning bridges – has been brought home by reports that perennial dropper of clangers Donald Trump used vulgar language to disparage certain nations from which people have moved to set up new lives in the US.

Trump’s apparent outburst against Haiti and countries in Africa occurred at the very heart of his workplace, the Oval Office, and was heard by a number of legislators from both the Republican and Democrat parties who were with him at the time to take part in sensitive, bipartisan talks on immigration.

It’s an extreme case, of course. But far away from the hallowed halls of American political power, the spectre of larky chat – often known as ‘banter’ – spilling over into something more sinister has been highlighted as a pressing problem for the workplace.

In evidence on the subject before the Women and Equalities Select Committee on 10 January, ACAS diversity chief Julie Dennis said: “We have had calls where older workers are talking about language used in the workplace and that younger workers are using language now that many of us would not deem appropriate … Because of youth culture, they’re coming out with certain statements or words that many of us in the workplace are quite taken aback with – so there’s that culture of banter and not understanding language.”

TUC senior policy officer Hugh Robertson added: “Language evolves … However what does not change is that any offensive terminology has no place at work. This is not about generational understanding – it is about respect for your colleagues, whether young or old.” With all that in mind, then, which classic signs show that ‘banter’ is slipping out of control and becoming something altogether unacceptable?

The Institute of Leadership and Management's head of research, policy and standards Kate Cooper says: “Surely, the rule here should be that if particular turns of phrase, or ways of discussing certain topics, make someone feel uncomfortable, then their discomfort eclipses the speaker’s own assessment of what they have said. Often, a speaker who has caused visible offence in an inappropriate context will try to play down the effects of their words. But that whole, ‘Oh don’t be so silly’ mentality is unequal to the offence itself. People are entitled to feel discomfited.”

Cooper notes: “Robertson makes a great point with his remarks on inter-generational communications: by and large, people do talk to their grandparents, parents and siblings in very different ways – and we also use different types of language for speaking in different settings. Men and women will also tailor and pitch their language in specific ways when they are in same-gender groups – although it will be interesting to see what sort of effect gender fluidity has on that dynamic. So the upshot of all this is that, unless you’re quite socially insensitive and unable to pick up on the cues that stem from the people around you, then the rules of the road should be eminently clear.

“Just recently, I was on a train next to a group of young women in their 20s who were being extraordinarily liberal with a particular expletive that would never pepper conversations between people of my generation. But I suspect that those same young women wouldn’t speak that way to their grandparents.”

Cooper adds: “In the workplace, the use of inappropriate language may arise from an attention-seeking mentality, or ageism – or, indeed, a number of other ‘isms’ – and the effect is to dominate the airwaves and say, ‘We are more important than you.’ But if we refer to Google’s landmark study on workplace behaviours, we can see that the most productive habits emerge from a climate of social sensitivity. So on that basis, it’s clear that language louts who go out of their way to alienate people aren’t so important after all.”

The Institute is holding two events on this topic – Banter: Just a bit of fun or crossing the line? – which are FREE for its members

To attend the 17 January event (London), book here

To attend the 5 February event (Manchester), book here

For further thoughts on effective communication, check out these learning resources from the Institute