Retroflex is a phonetic feature that does not exist in Japanese.

A dorsal sound is a sound that is pronounced by the back of the tongue approaching or touching the palate or pharynx.

A front vowel is a vowel that is articulated with the front part of the tongue.

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

A central vowel is a vowel that is pronounced in the central part of the tongue.

Front vowels are pronounced using the front part of the tongue.

There are various ideophones in Japanese.

'Beautiful' and 'pretty' are synonyms.

He is learning Nahuatl.

He can speak Azerbaijani.