3 toxic phrases that highly successful people never use, according to psychologists and public speaking experts

Highly successful people often have at least one trait in common, psychologists say: Their inner monologues are positive and optimistic.

That can be a crucial element of achieving success: It's hard to achieve a goal or reach a milestone if you constantly tell yourself that you can't. Negative self talk can have a long-lasting impact over time, leading to anxiety, depression and a long-term hit to your confidence, research shows.

Here are three toxic phrases that successful people never say to themselves, according to psychologists and public speaking experts.

More than 80% of people face feelings of impostor syndrome in their lives, research shows. This can prompt you to use phrases like "I'm not worthy of my success" or "I don't deserve this," according to Christina Helena, a public speaking expert and TEDx speaker.

"Ask yourself: 'Why do I believe I don't deserve this?' If the answer is because your goals don't align with someone else's blueprint for success, acknowledge that feeling, and then let it go," Helena wrote for CNBC Make It last year.

"Once you identify where that attitude comes from, it will have less power over you," Helena added. "Success looks different for everyone. Ultimately, you get to decide whether you deserve the good in your life, and what you've worked so hard for. "

In a world where people constantly broadcast their life's highlights on social media without disclosing their hardships and setbacks, you may start to believe that other folks are better than you. 

Maybe you feel like you'll never measure up to the people you most respect and admire. You may tell yourself, "I'm not as good as them" or "I'll never have the life that they have."

"Rather than focusing on the fact that you're not as beautiful