You don't say!
Не может быть! Что вы говорите? Неужели?
"Your ring is a real diamond? You don't say!"
- you can lead a horse to water (but you can't make it drink)
- you can't teach an old dog new tricks
- yoke around (someone's) neck
- You scratch my back and I'll scratch yours.
- You bet your boots!
- you can't make an omelet without breaking the eggs
- you've got to hand it to (someone)
- young at heart
- year after year
- year in, year out
- year round