A good manager should know not only what to say to his subordinates to motivate them but also what not to say if he does not want to demotivate a lose them. Let's recall the basic mistakes in communication with subordinates as described on Forbes.com.
"I pay you to work, so do what I say."
Threats don't work as a motivating factor and a good leader doesn't need them. He rather follows the way of inspiration, encouragement and development of his subordinates.
"Be happy that you get a bonus. Another company wouldn't give you anything."
It is much more efficient as well as more enjoyable to feel happy when you can reward someone for his help to your common organization that to look down on your subordinates.
"I work in the evenings and on weekends, why don't you do the same?"
Employees shouldn't feel that they are required to be ready to work 24 hours a day, 7 days a week. It only lowers their morale. It is just your private matter for how long you work.
"We don't want you to leave us because we don't want to look like discriminating against women."
Any hints of discrimination won't help employees to feel better for you. Though not illegal, it is rude.
"We need to reduce costs."
This should not be heard from your mouth especially in situations when you clearly show to the people around that different rules apply to you (and you go to e.g. buy a new car). Especially in difficult times, a manager should be an example.
"Your complaints don't interest me."
A good boss actively seeks feedback including the negative one and has his door open for his people.
"We've always done it this way, I can see no reason to change it."
Rathe always ask what you can change for the better. And lead your people to think the same way.
"You are doing a bad job."
If so, ask whose fault it is. Your people need to hear from you what specifically you expect and get the resources that will help them achieve it.
"You are a stupid person and my worst employee ever."
A manager shouldn't get angry in front of his and especially on them. When solving problems, you should maintain politeness and professionalism.
-kk-