He is majoring in philosophy.

He is pouring his passion into language study.

He is interested in geometrical shapes.

He is an expert in statistics.

My grandfather is being seen by a specialist in geriatric medicine.

I am majoring in biology at university.

He proposed a new theory about quantum mechanics.

He is an expert in petrochemistry.

He is an expert in folklore studies, and his research is highly regarded worldwide.

I have a deep interest in French literature.