Translation:The clouds are really beautiful!
-네 is used to express surprise or wonder.
크네: (it’s) huge!
Very useful, thank you!
"The cloud is very beautiful" should also be correct.
Trying to line up Korean and Japanese sentence enders is amusing, hah. 네 is like よ (and not ね), 요 adds politeness (yet hearing ㄹ까요 sounds like a mild attack if your head is in Japanese mode). What fun. :P
雲 は きれい だ よ。
So there is the exclamation mark at the end of the sentence.
'clouds are really beautiful' was not accepted
the clouds sure are beautiful!