Whether dealing with clients, coworkers or superiors, how you phrase and frame your message colors the way people perceive you. The words you choose may be the difference between being thought of as problem-solver or a problem."Words are very important because they shape not only how other people hear you, but how they feel about you,” says Karen Friedman, author of Shut Up and Say Something: Business Communication Strategies to Overcome Challenges and Influence Listeners. "If you garner some kind of positive emotion, then you’ll make people care. Then you’re in a much better position for them to listen.”However, too often business communication is peppered with filler words (umm, uh huh, well) that muddle the message, qualifiers (sort of, kind of, mostly) that diminish authority, and negative framing (can’t, impossible, never) that is discouraging and unproductive. In an informal poll of communication experts and career advisers, these 10 phrases were voted the worst things to say in your career.That’s not my job."This makes it about what you can’t do as opposed to what you can do,” says Friedman. "It paints you as not being a team player.” Furthermore, it flies in the face of crucial career assets like flexibility and the willingness to learn new skills, which are required for leadership roles. Take it to a positive place by saying, "It’s not really my area of expertise. Let’s see who might be able to better help with this.”I think…Lorrie Thomas Ross, chief executive of consultancy Web Marketing Therapy, calls this and others like it ("I believe” and "I feel”) "discounting phrases.” They make you seem less authoritative and reduce the power of the message.The statement, "I think this is the best strategy,” is much weaker than, "This is the best strategy.” Likewise, eliminate prefaces like "I want” or "I’d like to.” So, rather than saying, "I want to thank you,” simply say, "Thank you.”I don’t know."You think that’s being honest, but it’s really a cop out,” says Henry Devries, assistant dean for continuing education at the University of California San Diego and co-author of Closing America’s Job Gap. "It can be seen as lazy and not willing to take the next step.” Instead, say: "Let me find out the answer.” Similarly, saying, "I don’t know how to do that,” is better framed as, "Where could I get help to learn how to do that?” Then, you’re bridging the solution.I can’t.Again, this suggests a rigidity and unwillingness to be helpful or provide solutions. "You want to show employers you are ready to learn and tackle any challenge,” says Josh Tolan, chief executive of video interviewing platform Spark Hire. Instead of dismissively saying "I can’t,” pinpoint the issue and suggest a way around it. For example, if you’re asked to present a project at a time that conflicts with another commitment, say, "Unfortunately, I have a conflict then. However, I’ve been working closely with Sarah on this, and she would be fantastic.”But…"Using the word ‘but’ completely negates whatever you’ve said before it,” says Devries. While you may be well-intentioned, a comment like "that blouse looks nice on you, but the earrings don’t match” will not be taken well. We are conditioned to always listen for the negative information."We’re used to the manure sandwich,” he says—that’s something nice, something negative, something nice, so that the negative bit is sandwiched in between. Oftentimes, "but” is easily replaced with "and,” which softens the message.That’s not a good idea.Nancy Mobley, founder and chief executive of consultancy Insight Performance, says quickly shooting down ideas makes employees and coworkers feel less comfortable about sharing their opinions and ideas, which can hamper creativity and innovation.  "Some of the best ideas might be something you’re apt to shoot down before vetting them and getting more information,” she says. Instead of dismissing something outright, ask a question like, "How would it work?”I’ll try."The word ‘try’ implies the possibility it may not get finished; it presupposes possible failure,” says communication expert Darlene Price, author of Well Said. If your boss asks for a proposal first thing in the morning and you respond, "I’ll try to get it finished,” you’re undermining yourself and putting doubts in your boss’s mind. Instead, say, "I’ll have it on your desk by 9 a.m.”It wasn’t my fault."People hear it as defensive,” says Friedman. If someone asks what went wrong, they may not even be blaming you, so immediately diverting blame only draws attention to it. Take the higher ground, and try to be a problem solver. Say, "Let me try to better understand what happened,” or, "Let’s figure out how we can prevent it from happening again.”I guess.This is a common qualifier, which people use to hedge their bets against saying the wrong thing. "Avoid language that is tentative and not reflecting confidence,” says Dale Austin, director of the career development center at Hope College. Erase it from your vocabulary.If there’s a concern that gives you pause, instead of speaking tentatively, express the concern outright.That’s impossible.Like saying "it can’t be done,” "that’s impossible” is extremely negative. "It signifies that you’re not willing to even try,” says Friedman. "Negativity is infectious and spreads like a virus.” To keep it positive, say, "Let’s look at some different ways to tackle it.”Forbes.com