He is interested in toponymy.

His toponymic surname indicates the region from which his family originates.

The place of articulation is a very important concept in phonetics.

The potential energy of this ball is proportional to its height.

His usual location is the seat at the very back of the library.

I am studying Korean language.

I am learning how to use the present participle in English.

The present tense is used to express things that are happening now or general facts.

Let's start the meeting according to Korea Standard Time.

Ninsaburo is my best friend.