You love your job, and you love leading your employees. You're full of optimism for your company, your product, and your team, and you express that optimism every chance you get. You know how important it is to everyone's success that you feel and speak like a winner. But are your employees feeling and speaking the same way, especially when you aren't listening?

Probably not, according to Daniel F. Prosser, author of THIRTEENERS: Why Only 13 Percent of Companies Successfully Execute Their Strategy--and How Yours Can Be One of Them. Words can be powerful motivators, he says, and speaking your goals and desires out loud is an effective step toward making them come true. But just as words can be powerful forces for good, they can act just as powerfully to demotivate employees if they're hearing--or saying--the wrong ones.

Unfortunately, that's what's happening most everywhere, he says. "Conversations in nearly 90 percent of companies are limiting, and they undermine and sabotage the company's performance." Even more unfortunately, he adds, most bosses have no idea.

Don't let this happen to you. It's great to try to find out what your team members are saying, but it's even more important to make sure you never give them a reason to feel negative. Here are ten phrases Prosser says are particular danger signs, and how to change those sentiments:

1. 'It's not our strategy.'

Do your employees feel that they have a hand in guiding your company or department's direction? Or are they just being asked to execute tasks and reach goals they had no part in deciding? If it's the latter, then it should come as no surprise if they feel disconnected and unmotivated, Prosser says.

The answer is simple, he says: Give everyone a seat at the table. "Ask them for their insights and opinions regarding the path your company is on and how they see themselves fulfilling their roles. Don't just talk about 'engagement' and 'empowerment.' Allow people to contribute, ask questions, and even disagree with you." This will get them invested in the company's goals and give real meaning to their work, he says. (Here are some more ways to empower employees.)

2. 'They don't appreciate us.'

If you're the boss, you may find it challenging to thank employees, or give them genuinely heartfelt praise. You may even fear possible negative consequences--inciting envy among other employees, or even worse, being asked for a raise.

If so, you're not alone Prosser says. Even among highly successful, highly skilled executives, he says, "I've rarely found one who is totally comfortable authentically (meaning from the heart) acknowledging or expressing appreciation for an employee in front of others."

But if this is a common problem, it's also a dangerous one, he says. So get over it. "It can cost you big-time not to have that conversation," he says. "It costs you nothing to appreciate and acknowledge the contributions of others." (Here are some more reasons it's smart to both praise and thank employees every chance you get.)

3. 'They're always making excuses.'

This too is a dangerous phrase because accountability has to start at the top. If employees see managers making excuses for their failures or missteps, or--worse--blaming others when things go wrong, they'll do exactly the same.

And no one is likely to tell you this is happening. "Honestly--how comfortable would you be calling your own boss on the carpet?" Prosser asks. "It's time to become publicly accountable for your own results--good and bad. You'll find that your people are much more willing to follow a fallible leader with integrity than a 'perfect' leader who constantly passes the buck."

4. 'Did you hear [what one employee said about another employee]?'

Gossip is common everywhere, but negative gossip about an employee should always be unacceptable in your workplace. How can you tell if something constitutes gossip? Simple, Prosser says. "If what is being said about another person can't be said to that person's face, it's absolutely gossip. Wherever there are secrets or anything that cannot be discussed at any level of an organization, you will find a dysfunctional organization that's unable to focus on what matters." That's a powerful motive for shutting down gossip and making clear that it won't be tolerated, ever.

5. 'What mission statement?'

Would your employees be able to tell you your company's or team's mission or vision if you asked them out of the blue? In most cases, Prosser says, the answer is no, and the fault lies with management.

"How can people implement actions or execute a strategy when they can't understand the relevance of your vision or mission as it relates to their jobs?" he asks. "Most teams don't openly discuss the mission of the company and its relevance to their marketplace focus. As a result, the significance of their role as an employee contributor isn't well understood."

That's a shame, because it means you're missing out on a powerful motivator. Knowing how their efforts fits into the overall picture, and mission for the company, is one reason employees at small businesses engage with their jobs. Don't pass up that engagement. Make sure the people who work for you know your vision and how they're helping to reach it.

6. 'They treat us like crap.'

You'd think most company leaders would make sure to treat employees with courtesy and respect. Not so much. In a 14 year study, 98 percent of employees reported being treated with rudeness at work. Half said it happened every week. When the study's authors asked 125 managers why they were rude, most said they just didn't have time to be polite.

Those bosses are undercutting their own bottom line. "Employees who feel that they're being treated badly will put forth the bare minimum of effort. Their negative attitude will be all too evident to customers. And they'll probably jump ship at the earliest opportunity," Prosser says.

You don't want that. "Treat your employees at every level with civility and respect," he declares. "Make sure all supervisors do the same. No excuses."

7. 'It's the same old story.'

Have you gathered everyone together to tell them your new vision/goals/inspiration for your company or department? Your grand pronouncements are likely to be met with eye rolling because most employees have heard it all before. Multiple times.

Today's sophisticated employees can always tell when a leader is being authentic, and when not, Prosser says. "They will usually give you one chance to get it right."

So be honest, be vulnerable, tell the truth about what has and hasn't gone well and exactly what you're trying to accomplish. Speak from the heart. When you do, employees will be able to tell.

8. 'Because the boss said so. That's why.'

That kind of thinking is a sure sign of a command-and-control culture, and that's not what you want. "Employees may buy into a patriarchal and paternalistic business culture because it lets them off the hook," says Prosser. "They can avoid having to make promises and take action." Worse, they may feel that they can and should do nothing until someone tells them what to do. "Those employees can't execute your strategy because they won't take responsibility for causing things to happen."

If any of this describes your company, it's time to make a drastic change. Give your employees both responsibilities and the autonomy to carry them out. Learn to trust them. Or you'll be stuck in the slow lane forever.

9. 'This is how we've always done it.'

That's never a good reason to do something. In fact, it's a recipe for getting left in the dust. So if your employees are thinking and talking this way, make sure they know they're both allowed and expected to challenge the status quo.

"Employees who haven't been shown that they can grow, develop, and expand their opportunities within the organization will lose interest in what you want," Prosser warns.

10. 'Just don't screw up.'

Unfortunately, this sentiment often starts at the top, often from a boss who's afraid of failure. Even if you're successfully avoiding failure, you're demotivating your employees at the same time, Prosser says.

"Leaders who are in constant fear of the unknown and uncontrollable events in their business need to get a grip," he adds. Otherwise, your employees will wind up feeling stressed, and focusing on placating you and calming your fears rather than executing your strategy. "There's no faster way to turn good employees into cynical and non-productive ones."