He continues to beat his head against a stone wall, even though he knows it's futile.

I don't know my head from my ass.

The heads-up display in the car shows important information such as speed and navigation directions.

The heads-up displays in modern cars provide important information to the driver.

The museum has a collection of King Charles' heads.

The museum has a collection of King Charles's heads.

Let's put our heads together and come up with a solution.

Cool heads prevail in times of crisis.

In times of conflict, it is important for cooler heads to prevail.

Cool heads will prevail.