The boss-employee relationship can be a precarious one. Even the best managers may have difficulty communicating at times, especially if an employee’s behavior is frustrating. Whether you’ve been at your job for a few months or more than a decade, it’s important to realize that your words make a big difference in how your boss perceives you. Here are a few phrases you should avoid.

1. “That isn’t my job.”

You may have a very specific job description, but employees excel by doing whatever it takes to make an employer succeed. Always be ready to do more than expected or learn how to do something new. The result could be more job stability.

2. “I’ll quit if…”

Ultimatums tend to come across as threats, which likely won’t get the results you want. You may even find your boss calling your bluff, sending you straight to the unemployment line.

3. “I can’t come in today.”

An occasional sick day is to be expected but over time, a pattern of calling in can become a problem, whether it’s due to childcare issues, your own ongoing illnesses or just because you don't feel like it.

4. “I can’t afford to pay my bills.”

Frankly, it's not your boss's problem that you can afford things or not. When you accepted your position, you agreed to a salary, which may or may not have increased over time. Your employer’s sole responsibility is to issue that salary in the form of a paycheck.

5. “I’m just here to earn a paycheck.”

It really isn't smart to mention this, whether it's true or not. Employees who go the extra mile and put the needs of the business first will be at the front of the line for raises or promotions. Also, get a hold of yourself and go find a job that you have some passion for, if you find that you are always "phoning it in" at work.

Related: Ignoring Employee Morale Will Cost You. Here's the Solution

6. “It’s not my fault.”

When something goes wrong, avoid playing the blame game and instead focus on how you can work as part of a team to make things right.

7. “My last boss did it differently.”

Whether you’re talking about your previous employer or your boss’s predecessor, this information is irrelevant. Your current boss has every right to come up with a new approach.

8. “I can’t.”

In general, you should strike the word “can’t” from your vocabulary, but this is especially true when your boss asks you to do something. Always show a willingness to give your best effort.

9. “You didn’t tell me to do that.”

Even if your boss neglected to mention something, pointing that out won’t win you any points. Instead take the high road and promise to get right on whatever task needs to be done.

10. “I’m so sleepy.”

Even if you’ve been up all night working or caring for your infant, your boss doesn’t need to know about it.

Related: Managing the Unmanageable: The 6 Most Common Types of Difficult Employees

11. “It’s unfair.”

Comparing yourself to coworkers only makes you look petty and jealous. Instead highlight your own attributes and impress your boss by executing your duties well. Avoid pointing out any preferential treatment you believe others may be getting.

12. “Sorry I’m late -- I had a job interview.”

It may seem crazy, but this happens more than you might think. No matter how strong your relationship is with a supervisor, there's no need to mention this. If you choose to look for a job, do so behind the scenes, during lunch breaks or after hours.

13. “I’m bored."

Instead of complaining about your empty to-do list, look around for ways you can help others lighten their workload. If you’re ready for more responsibility, let your boss know you want to tackle additional challenges and name specific things you’d like to learn.

14. “You’re wrong.”

At some point in your working relationship, your superior will be wrong. When that happens, point it out diplomatically, using words like, “I might be mistaken, but I thought…” instead of bluntly insulting your boss. If you correct your boss the right way, they may end up respecting and trusting you more.

15. “I quit.”

No matter how hard things get, never utter those two words in the heat of the moment. Always resign with two-weeks’ notice and only after you have a plan for replacing your income. More than that, look for a job or a team of people that won't leave you on the edge of quitting so easily.

Related Book: No B.S. Ruthless Management of People & Profits by Dan S. Kennedy

Communication is essential to career success. When you’re trying to impress your boss, it’s important to know the right words to use. Even a small, offhand statement could send the wrong message, damaging your career for years. Remember, if you're not sure whether what you're about to say may be received well, give it a second thought. You may just need to rephrase it, or keep your mouth shut.