Learning English~Persian: Idiom: Take pains to do something/Be at the mercy of somebody #132
Take (great) pains to do something = To work carefully and conscientiously, make a great effort.
She takes pains to do everything well; she's our best employee.
He took great pains with his last assignmnet because he needed to get an excellent grade to pass the class.
Both sides are taking pains to avoid any appearance of disagreement.
Be at the mercy of somebody = Be under the control of somebody.
Do you think Mrs. Parker will help us.
Only if her husband allows her. She’s at the mercy of her husband.
Poor people are increasingly at the mercy of moneylenders.