No, you cannot have a flat screen monitor.
No, I cannot finish that five year plan by Friday.
No, I will not pay for that.
No, you have to listen to me, I'm the boss.
No, I haven't read your email yet.
No, you can't have a raise or a promotion.

Yes, if I ask you to make something work, I expect it to work.
Yes, I'm busy.
Yes, I expect you to make a decision.
Yes, I have a problem with that.
Yes, that plan will piss people off.
Yes, I already told you the answer.