Voicing your opinions at work isn’t always easy—especially if you want to disagree with your boss. But if you want to stand out, move up and make more money (research has shown that disagreeable men and women earn 5% to 18% more money), knowing how to agreeably disagree with your superiors is an essential skill.

Here’s how you can use assertive behaviour, the middle mark between passive and aggressive behaviour, to speak up without stepping too far out of line.

Never say never

Telling your boss that, “It always takes forever for our team to submit a proposal because we don’t have the right technology,” sounds harsh and aggressive. Instead try saying something like, “The last three times our team submitted a proposal, it was late. I think that implementing new technology could fix this problem.”

Using absolute or hyperbolic terms like never, always, forever and impossible can come across as an attack and won’t add credibility to your argument. Instead, speak in specifics, using examples and anecdotes to add supporting evidence to your argument.

There is an “I” in team

Though they say there’s no “I” in team, when approaching conflict, speaking in “I” statements rather than “you” statements will work to your advantage. For example, the statement, “You don’t need to micromanage my workload,” can be better said by stating a fact and then a feeling: “When you check in on me every few hours, it interrupts my workflow, and I feel like you don’t trust me to get the project done.”

Using “I” statements instead of “you” statements helps to target the exact behaviour that is bothering you, rather than projecting that behaviour onto your boss or coworker’s character.

Body language best practices

Body language accounts for 55% off the message you’re trying to send. Though you may be using the right words, if you’re saying them too quickly or loudly while hovering over your boss’ desk, your body language is more likely to be heard than your intended message.

If you find yourself eager to disagree, take a second to adjust your tone of voice and posture, make direct but non-confrontational eye contact and speak rationally about the issue by using specific examples or stats.

Watch and learn

The best piece of advice I received when taking an assertiveness training course was to look for communication role models at work. Whether they are extraverted or introverted, they’re the smooth talkers who seem to always know what to say, when and how to say it. By looking for great (and not so great) communicators in your everyday life, you can learn from real world examples how—and more importantly how not—to tackle awkward or sensitive communications scenarios at work.

Communicating assertively shows excellent leadership qualities, which could put you in line for a promotion. Just remember to always respect other opinions, and to keep your opinions to yourself until your boss’ boss leaves the room.