You can hear it in their voice.

When an employee, contractor, business partner, or even a customer is not planning to deliver on what he or she has promised, you can always tell. Listen to the exact wording, voice inflection, and maybe a hint of deviousness, but these phrases are always a red flag. They reveal the person intends to fail.

1. "I will do my best."

If you hear this one, make a contingency plan. The person is not going to do their best. In fact, it's a warning sign that the person already knows they cannot complete the task. Whatever happens, it will end in failure.

2. "Let me get back to you on that."

I've heard this one at trade-shows many times. It means the exact opposite. The person saying this phrase won't get back to you--ever.

3. "I have some good ideas on that."

It's a red flag when people tell you about an idea. It's a stall. If the idea was that great, the person would just do it and the problem would be resolved.

4. "I will try."

Not everyone has seen the original Star Wars movies. There is no try, per Yoda. When someone says "try," it's a code word. It means: "I know I am going to fail."

5. "Actually, ..."

This is a harmless word, right? Yet, it means trouble. What comes after it is a mild rebuttal, but the person is not really that sure. "Actually," they are planning to fail.

6. "You have my word on that."

Confident people don't use this phrase. Why bother? The person who needs to trust you will either do that or won't do that, despite whether you say this phrase.