だんだん暗くなりつつある。

だんだん暗くなりつつある。

It is getting darker and darker.

だんだん暗(くら)くなりつつある。

Dandan kuraku nari tsutsu aru.

段々 (だんだん)

gradually; by degrees; steps; stairs; staircase; terrace

暗い (くらい)

dark; gloomy; dark (in colour); dull; depressed; dispirited; sorrowful; bitter (as in a dark past); unclear; unfamiliar; unknown

なる (なる)

that is in; who is called; that is called; that is

つつ (つつ)

while; even though; despite

有る (ある)

to be (usu. of inanimate objects); to exist; to live; to have; to be located; to be equipped with; to happen; to come about

Readings: アン、くら.い、くら.む、くれ.る

Meanings: darkness, disappear, shade, informal, grow dark, be blinded