to be on cloud nine: to be very happy because something great happened
E.g. He was on cloud nine when he heard that his wife was pregnant with their baby.
I would be on cloud nine if I got that promotion!
come rain or shine: no matter what happens, it is done
E.g. The mailman comes every morning, rain or shine.
Come rain or shine, I'll be at your wedding, I promise.
when it rains, it pours: when something goes wrong, it will be followed by a serious of negative events
E.g. Last week Tom got fired, his girlfriend broke up with me, and he got the flu. When it rains, it pours.
It looks like everyone in our family is sick again, and all at the same time. When it rains, it pours.
a breath of fresh air: a relief in the form of a person or situation
E.g. I love his innovative ideas and drive. His positive attitude is a breath of fresh air in this cut-throat industry.
Leah is so cheerful and optimistic- she's like a breath of fresh air when we meet.
under the weather: not feeling well
E.g. I don't think I'll be able to make it to work today. I'm feeling a bit under the weather.
Jane has been feeling under the weather for a few days. She is going to see the doctor today.
to take a rain check: to postpone something for another time; a coupon for a sale item that is temporarily out-of-stock
E.g. A: Why don’t we go out for lunch today? B: I’m sorry, I need to take a rain check, I have an important meeting at noon. We can get together another day.
The detergent was on sale in the store but they ran out of it. I got a rain check from the clerk so I can go back and get it at the sale price when they have it back in stock.
shoot the breeze: to chat in a relaxed way
E.g. We spent the entire afternoon just shooting the breeze with Joel. It was good to chat with him at last.
They say girls like to talk but I know that the guys like sit around the locker room and shoot the breeze too.