He has morally degenerated.

This hardened dirt is so hard, nothing can be planted.

A central vowel refers to a vowel where the position of the tongue is in the middle.

The central vowels in Japanese are 'a', 'e', 'o'.

It is said that this area used to be a mass grave.

My grandfather was a teacher at a national elementary school.

My friend goes to a Korean school.

My friend goes to a Korean school.

School grammar is the foundation of Japanese education.

My younger brother goes to a school for special needs.