What frequently occurs as you prepare your witness (usually the client) for deposition or trial, is a resounding “That’s a lie!” to your best attempt to replicate what will be opposing counsel’s “Isn’t it true…” questions.
For all that it may be highly satisfying for said witness to roar “Lie!” it is not good juror strategy. Jurors are best persuaded when they come to the “Lie” conclusion on their own. Encourage your witness to respond to what they consider a “lie” with phrases such as “That is incorrect,” or “That’s not correct,” or “That’s not how I experienced it,” or some such.
Reassure your witness that at trial, the “lies” will be revealed for the jurors, for example through a “Chart of Inconsistencies.” As defense, for instance, you could bullet on a chart what the plaintiff told Dr. A, the different story he told Dr. B, and the yet more different tale he told at deposition. Or as plaintiff, you could bullet on a chart what defendant told the police, what was discovered in emails, what she swore to in interrogatories. Such a chart alone, since it references facts, has more impact on today’s jurors than your witness’s forceful expostulation “And he lied!!” ever could.
Once your witness understands that you will not let the “lies” go undiscovered, he or she will more readily accept your recommendation of “incorrect” as a valid alternative.