He went to North Korea to learn the cultural language.

It takes time to read this long text.

Adding fractions is difficult.

Learning how to use past participles is important for understanding English.

Each element of this set has a unique characteristic.

This sentence is very long.

He is our boss.

He worked late into the night to complete his doctoral thesis.

I am solving integration problems in math class.

He is majoring in liberal arts at university.