dark与darkness

dark 作名词的时候, 只能用在以下短语中:

(1) the dark : when there is no light, especially because the sun has gone down:
例句 : my childish fear of the dark
in the dark
例句 : I turned off the light and lay there in the dark.
例句 : We stood outside in the pitch dark (=when there is no light at all).

(2) after/before/until dark = after, before, or until the sun goes down at night:
I want you home before dark.

(3) in the dark = knowing nothing about something important, because you have not been told about it:
例句 : We're in the dark just as much as you are.

darkness 做名词用在以下三种情况

(1) when there is no light:
例句 : the long hours of darkness during winter
in darkness
例句 : The lamp suddenly went out, leaving us in darkness.
total/pitch/complete darkness
例句 : The room was in total darkness.
例句 : We lit our campfire as darkness fell (=it became night).
例句 : He stared out th