Grammar is an empirical science, not a theoretical one.

He also discovered sunspots, the dark areas of the Sun. He saw that the planet Venus has light and dark phases just like the Moon. These discoveries provided empirical information that proved that the Sun is at the center of the Solar System, as Nicholas Copernicus had predicted.

All humans are mortal" is an empirical observation based on millennia of experience.

As of yet there has been no empirical research done on this subject.

The empirical data from this experiment seems in line with the theoretical hypotheses.

Empirical data is based solely on observation.

Philosophy is a science, and as such has no articles of faith; accordingly, in it nothing can be assumed as existing except what is either positively given empirically, or demonstrated through indubitable conclusions.