坑内 こうない 炭鉱 たんこうじゃありません
kō nai horitankōjārimasen

Noun
Desu Copula
Negation Auxiliary

The polite negative form of 坑内掘り炭鉱

1. It is not a coal mine.; It's not a pit coal mine.

Negative
Polite
Terminal Form