He is studying late into the night to learn a new computer language.

Learning Modern English is important for smooth international communication.

He is interested in the study of constructed languages.

He remained silent and didn't say anything.

He was promoted to Admiral of the Fleet.

I am planning to go to Copenhagen next week.

He is an expert in sociolinguistics.

I am very interested in sociolinguistics.

He is an expert in nuclear physics.

He has already finished writing the report, so we use the present perfect form.