For those in business who do not have English as their first language, mastery of its nuances could help make a deal rather than break it.
Language expert Sarah Taylor, who recently launched the phonetically- based Colloquik programme with communications consultancy The Aziz Corporation, says the trouble often begins once formal meetings are over.
"Most business people have a good knowledge of English, and know their own jargon well, even if they can't pronounce it properly, but when they have to go out to dinner, it's much harder talking generally. We're not teaching them English; we're trying to perfect what they already know."
Ms Taylor says the Japanese and French tend to struggle to pronounce the letters L and R; the difference between the "th" as in "the" and "thick" can also be tricky. The individually-tailored programme uses repetition and mirror-teaching to build up confidence.
Khalid Aziz, of The Aziz Corporation, said Colloquik was devised after he conducted a survey on the effects of an accent.
"Most people have a fairly short concentration span and if they have to struggle to understand a strong accent they are less likely to take on board what is being said," he noted.
It is essential to bear in mind that communication is receiver-driven, according to Lee Bowman of The Kingstree Group, which specialises in spoken communication skills.
"There are figures of speech that you use if you don't feel you've got the feedback. The way most people approach making a presentation is to make adjustments at the transmission end without taking into account that it's receiver-driven."
He say Prime Minister Tony Blair, for example, should use his natural style rather than studied gestures. "A number of them come directly from John F Kennedy, such as the way he makes a fist with his thumb and forefinger. They're all practised.
"John Major was a classic example. People would tell you that over a drink he was great fun, but the minute someone pointed a TV camera at him, he felt he had to use sentences, and it came across as boring."
Mr Bowman, author of High Impact Business Presentations, who numbers British Airways, Rank Xerox, Adidas AG and Eurotunnel among his clients, stresses the need to look natural.
"We see an enormous number of presentations that are driven by slides; people put them together, then try and figure out what they are going to say. They feel: 'People will be looking at what is on the screen and won't be looking at me - yahoo!' But they don't step back and say: 'How does normal communication work?' Relaxed conversation is where the best communication occurs.
"We're saying: 'If you could approach talking at the Institute of Directors conference in the Albert Hall in the same way as having a conversation with two or three friends, wouldn't that be a good thing?'"
For details of Colloquik, tel: 01962 774 766. 'High Impact Business Presentations' is published by Business Books at pounds 16.99. For more information about The Kingstree Group, tel: 0171-836 5575.