Simple:
* Professor Smith teaches history at the university.
* The professor gave a fascinating lecture on quantum physics.
More complex:
* The students were eager to learn from the renowned professor in the field of astrophysics.
* After years of research, the professor published a groundbreaking book on the evolution of language.
* Despite his intimidating reputation, the professor was known for his kindness and willingness to help his students.
Using "professor" with different meanings:
* She addressed the guest speaker as "Professor Jones," even though he was a doctor. (Here, "professor" is used as a title of respect)
* The new student felt like a professor compared to his classmates, who had no experience with the subject. (Here, "professor" is used figuratively to mean "expert")
Remember to use "Professor" with a capital "P" when referring to a specific person with that title.