I am thinking of learning Greek.

His native language is Spanish.

They are using English as a common language.

He always speaks in polite language, so he is considered very courteous.

His laughter can be expressed with the onomatopoeic word 'gyahaha'.

We swear to be friends forever.

He can speak African American Vernacular English fluently.

Learning Modern English is important for smooth international communication.

I am studying Modern English.

The water of this river is muddy.