“Can you lend me a hand with this typing, Sakamoto-san?”
An old hand
A very experienced person
“I’d ask Moriya-san for advice. She’s an old hand at brochure design.”
Out of hand
Out of control
“Giving an employee a salary advance isn’t a problem as long as it doesn’t get out of hand.”
Show one’s hand
To reveal one’s position
“It would be a mistake to show our hand by announcing our newly discounted prices at the trade show.” Note: this phrase is from card playing; showing one’s hand is revealing one’s cards to another player.
Change hands
To change ownership
“That condominium has changed hands three times since it was built.”