He can speak Russian fluently.

He is learning Latin.

I am interested in learning Celtic language.

I have been to Mongolia.

Learning the Erzya language is difficult.

This algorithm significantly improves the speed of data processing.

He had two children with his second wife.

She was devastated by sadness and wailed.

She wailed in overwhelming sorrow.

The era of the Five Good Emperors is considered the golden age of the Roman Empire.