Watch What You Say When you open your mouth, do you drive away business?

Ask any English professor or business communicator, and you'll receive the same answer: Whether you're speaking to the public or chatting with an investor or vendor over lunch, the quality of your vocabulary affects your company's bottom line.

It's not surprising that grammarians and business experts don't recommend botching the language to the point where you interchange the words good and well. "It isn't uncommon, even at fairly high levels of business, to find people who have never been told they're using improper grammar," says Suzanne Bates, president and CEO of Bates Communications, a consulting firm that helps executives and professionals improve their speaking style. "Even if people aren't telling you you're using incorrect grammar, people are evaluating you, and often concluding you're not intelligent," says Bates, author of Speak Like a CEO: Secrets to Commanding Attention and Getting Results.If you consider yourself educated and articulate, you have cause for concern, too. People can come to the same conclusion--that you're an idiot--if your vocabulary comes off as too erudite.