べん
benga tatsu

Godan Verb (tsu)
Expression

1. to be eloquent; to have a way with words

彼女 かのじょはあまりしゃべらないが、いったん くち ひらくと べん つ。
kanojowa amari shaberanaiga ittan kuchio hirakuto benga tatsu.
She doesn't talk much, but once she does speak she is eloquent.