We pay a lot of attention to looking professional in the workplace, but we don't always give enough thought to sounding professional.

What you say and how you say it goes far in telling those around you how serious you are (or aren't).

Here are some phrases you can hear every day in many workplaces. Whatever the intent of the speaker, the real message they send is that they're inexperienced or uncommitted--not exactly the impression most people want to leave. If you ever catch yourself saying any of these things, put a stop to it at once:

1. "It's not my fault."

There's no way to keep this from sounding whiny and blaming. It doesn't even matter if it's true--it leaves a bad impression. Take ownership and accountability for the things you do, and when something goes wrong, keep the focus on solving the problem and preventing a recurrence rather than blame. To make a mistake is part of learning, but to make excuses and to blame others is a career killer.

2. "I can't."

When you say you can't do something, you demonstrate a lack of confidence and unwillingness to take risks. Instead, try one of these options: "This is new territory for me, but I'm willing to take it on" or "Can I call on you if I run into snags?" or "Sure, I'd love to learn how to do this."

3. "I'm not willing to."

If you say you're unwilling, you're backing down from a challenge--and you're saying that your priorities are more important than the team's or the organization's. If you want to excel, you have to get comfortable with being uncomfortable.

4. "What's in it for me?"

If you think only of yourself and how you will benefit, you're going to be (correctly) perceived as self-serving--and most organizations have little tolerance or patience for those who refuse to be part of a team. To be successful, focus more on we and less on I.

5. "I can't work with her." (or him)
Choosing whom you will and won't work with makes you sound not only unprofessional but also immature. Learn to deal with conflict, and set differences aside when you need to. And if the other person's offense is truly egregious, like sexual harassment or threatening behavior, report it through the appropriate channels.

6. "I'm bored."
This may be the most damaging one of all. What are the people around you to think when you voice the fact that you find your work tiresome or tedious, insufficient to hold your attention? Your job is to find enthusiasm--or at least cheerful willingness--for everything you do. If you need more of a challenge, find a new activity to take on.

7. "I'll try."

Trying doesn't mean doing. You can try without being successful, or for that matter without really putting up much effort. If you try with determination and perseverance, you're going to get there--so say so! Instead of "I'll try," confidently say, "I'll take care of it."

At the end of the day, the best way to look and feel more experienced and professional at work is to listen closely to every word you say and ask yourself if it means what you want it to mean. Let your words serve you well, be your confident self, and you'll soon earn the respect you want.