Their original forms existed long before they were reduced to writing.

On stages around the world, an international form of pop music exists.

I admit that no form of life on our planet could exist under such conditions.

These forms are not exclusive, but exist at the same time.

The form no longer exists, and was probably a type of dance presentation.

While the form has existed for at least two hundred years, the focused study of it is fairly recent.

Different forms exist for first, second and third person entities.

We find that the republican form of society existed from the most ancient times known to us.

However, a form of glass strong enough to fully test the theory did not exist at the time.

The oldest forms of life existed 3.8 billion years ago, if not longer.