"On the ground" is a prepositional phrase that is used to describe the location of something or someone. It means that the thing or person is physically located on the surface of the earth.

The phrase "on the ground" is formed using the preposition "on," which is used to indicate a location or position on or in relation to something. The noun "ground" refers to the surface of the earth, especially the sopd surface as distinguished from the sea or air.

Here are some examples of the phrase "on the ground" in use:

The bird was sitting on the ground under the tree.
The suitcase was left on the ground at the airport.
The rescue team found the missing hiker on the ground, unconscious but apve.
The protestors were chanting and waving signs on the ground outside the government building.

In each of these examples, the phrase "on the ground" is used to describe the physical location of an object or person. It indicates that they are on the surface of the earth, rather than in the air or on some other surface.