"하늘에 구름이 꼈어."

Translation: There are clouds in the sky.

[LiKenun]

To make sense of why the past tense is used reinterpret the literal translation this way:

Clouds were hung in the sky.

The result of clouds in the sky is the present state we call “cloudy.”

[fbr_brazil]

Thank you for existing Kevin Li.

[nleconte]

The most blunt but real compliment one can give :)

[YunisR]

You're extremely helpful as well ☺

[nleconte]

Very helpful, thank you!

[ShaileeKap]

Thanks to you and @nleconte for your straightforward and easy to understand explanations. Both of you have helped me immensely.
감사합니다

[Pamela909830]

Could this sentence also be written "하늘에 구름이 있어요" or not?

[Iron_Venema]

Yes possible

[Pamela909830]

I am still wondering. Aug. 13, 2019

[spawn6000]

Also wondering...

[Pamela909830]

I am still wondering. Nov. 24, 2019.

[oee16]

Of course.

하늘에 구름이 꼈습니다 is just a pictorial way of saying "The sky clouded over/ (is/was) clouding over"

Worth noting:

The sky is cloudy/It's overcast = 하늘이 흐립니다.

[ 흐리다 used for weather, means to be overcast ].

[lameskydiver]

You can, but it's more like 'There are clouds in the sky' rather than 'It's cloudy'.

[oee16]

I think DLG translation doesn't reflect accurately the meaning expressed in the Korean sentence. Hence, the confusion.

끼다 is a motion verb -> cloud over. "Are" from "to be" is a static verb.

[mcguirepatr]

The words for cloud 구름 shadow 그림자 and shade그늘 share similar characters. Can somebody explain the etymology?

[okdal]

I'm no expert so take this with a grain of salt but they might be related through Hanja - the Hanja equivalent to 그늘 is 陰 which as you can see includes the character 云, an archaic word for 'cloud'. Considering how some radicals in Chinese characters influence how a word is pronounced, this might explain why they sound similar?
As for 그림자, the Hanja doesn't seem to resemble either word, but I did find someone claiming that the 그ㄹ part originally meant 'sun' so maybe there's a connection there.

[Iron_Venema]

I think 그림 in 그림자 means painting

[nogi132]

그림 means painting, 자 means person, so 그림자 (shadow) is kind of a painting of a person ("painted" by the sun)

[Pamela909830]

Thank you! That is helpful! :)

[hayakawa_masa]

Why only plural?

[Pamela909830]

I suppose you could say there is a cloud in the sky. However, that is a rare occurrence; usually we see more than one cloud. :)