The idiom "hard nut to crack" means a problem or a person that is difficult to understand or deal with. It is used to describe a situation or a person that is challenging to solve or overcome.
For example, if someone is trying to solve a difficult math problem, they might say, "This is a hard nut to crack." Or if someone is dealing with a stubborn person who refuses to change their mind, they might say, "He is a hard nut to crack."
The idiom is often used in situations where a solution or a breakthrough is difficult to achieve. It implies that the problem or the person is tough and requires a lot of effort and patience to overcome.
In summary, "hard nut to crack" is an idiom that refers to a challenging problem or a difficult person that requires a lot of effort to solve or deal with.
• She is a hard nut to crack when it comes to making friends.
• The mystery of the missing paintings is a hard nut to crack for the detective.
• The complex scientific theory is a hard nut to crack for even the most brilliant minds.
• The negotiation between the two countries is a hard nut to crack for the diplomats.
• The new employee is proving to be a hard nut to crack for the manager.
• The math problem was a hard nut to crack for the students.