He is serving as the president's guard.

He drew a pentagon on the blackboard.

What is this mixture made of?

Metalinguistics is an important concept in linguistics.

In this project, it is necessary to combine various data.

It's difficult to remember new words.

His native language is Spanish.

He can speak American English fluently.

Our company was able to succeed in a big project by federating with other small companies.

People from all over the country gathered to celebrate the emperor's birth.