As an adjective:
* The calm waters of the lake reflected the sunset.
* After the storm, a calm settled over the city.
* She remained calm even when faced with danger.
As a verb:
* The doctor advised me to calm down and take deep breaths.
* The music calmed her anxiety.
* The rain helped to calm the fire.
In a phrase:
* Keep calm and carry on.
* She has a calm demeanor.
* The situation is calm now.
Figuratively:
* Her voice was calm as she delivered the bad news.
* The calm before the storm was unsettling.
* He tried to maintain his calm despite the chaos.