1/ Yes man: A person who always agrees with his boss.

E.g. ‘Being a  yes man  keeps me out of trouble, and it might even lead to a promotion!”

2/ Call it a day: To quit work and go home; to say that a day’s work has been completed.

E.g. “ I’m tired . Let’s call it a day.”

3/Hit the nail on the head: To identify something exactly; to arrive at exactly the right answer.

E.g. “ He  hit the nail on the head  when he said the problem was the thermostat”

4/ Grey area (UK) / Gray area (US): Means something that is not clearly defined and needs careful judgement.

E.g. “It exists in a  grey area  between legal and illegal.”

5/ Get the ball rolling: To begin; to start some action; to set in motion.

E.g. We really need to  get the ball rolling on this project. The deadline is in October, and it’s already September.

6/ Thumbs Up: Shows that someone or something is good, especially when it comes to a performance or action with good results.

E.g. “That’s good. You deserve a big  thumbs up  for such a great presentation!”

7/ Big picture: Means the overall perspective or objective, not the fine detail.E.g. “Although we all have all specific tasks to do, our leader makes sure we don’t lose sight of the big picture.”