AMERICAN IDIOMS STARTING WITH Y
Year-round
Operating all year. ex. "This facility is open year-round."
Yes-man:
A person who tries to be liked by agreeing with everything said, especially by a boss.
You bet!
Yes! Sure! I agree! No problem!
You can say that again:
That is true (stress on "that"). ex. "It sure is hot today! You can say that again!"
You can't teach an old dog new tricks:
A proverb meaning that old people can't learn anything new.
You don't say:
Used to show surprise at something that is being said. ex. "You don't say! He was really struck by lightning?"
Your guess is as good as mine:
I don't know any better/ more than you know.