Being negative all the time
Repeatedly responding to suggestions with a pessimistic or contrary attitude can be construed as being uncooperative, Randall says. Phrases like "That won't work," "That sounds too hard," or, "I wouldn't know how to start," should be avoided.
Similarly, complaining too much puts you in a bad light.
"While there may be times when everyone feels the desire to complain about the boss, a coworker, or a task, voicing it will only make you look unprofessional," Randall says. "It's even worse if you complain every day, all day, from the moment you walk into work. Before long, people will go out of their way to avoid you."
"There's nothing as energy-draining as having to deal with a pessimistic coworker," Rosemary Haefner, chief human-resources officer for CareerBuilder, tells Business Insider. "Things do go wrong, but even when they do, focus your energy towards what you've learned from a bad situation."
She points to a recent CareerBuilder survey, which shows that a majority of employers — 62% — say they are less likely to promote employees who have a negative or pessimistic attitude.